----------------------------------------------------------------------------------
      name:  <unnamed>
       log:  /volumes/ddisk/math/soviet/Tables_3_and_4.log
  log type:  text
 opened on:  24 Mar 2014, 13:20:11

. use "/volumes/ddisk/math/ams/clean_ams_data_author_year.dta", replace;

. generate good=.;
(6282565 missing values generated)

. replace good=1 if year>=1970 & year<=1989;
(2433275 real changes made)

. egen n70=sum(good*papers), by(unique);

. drop if n70==0;
(675205 observations deleted)

. merge unique using "/volumes/ddisk/math/ams/international/soviet_universe.dta";
(note: you are using old merge syntax; see [D] merge for new syntax)
variable unique does not uniquely identify observations in the master data
degree_year was int now float

. drop _merge;

. keep if soviet==1;
(5243145 observations deleted)

. drop if emigre==1;
(31681 observations deleted)

. drop country;

. rename modal_country country;

. keep if year>=1982 & year<=2008;
(49365 observations deleted)

. sort unique;

. merge unique using /volumes/ddisk/math/soviet/shocks_and_instruments.dta;
(note: you are using old merge syntax; see [D] merge for new syntax)
variable unique does not uniquely identify observations in the master data

. drop _merge;

. drop if shock_idea_space==.;
(0 observations deleted)

. generate publish=(papers>0);

. summ publish papers ;

    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
     publish |    283169    .2871148    .4524164          0          1
      papers |    283169    .5506853    1.221365          0         29

. generate inter_shock1=post1992*shock_idea_space;

. generate inter_pexp1=post1992*shock_geographic_space;

. generate inter_paut1=post1992*shock_coauthor_space;
(76795 missing values generated)

. replace inter_paut1=0 if inter_paut1==.;
(76795 real changes made)

. generate inst_shock1=post1992*instrument_idea_space;

. generate inst_pexp1=post1992*instrument_geographic_space;

. generate inst_paut1=post1992*instrument_coauthor_space;
(58832 missing values generated)

. replace inst_paut1=0 if inst_paut1==.;
(58832 real changes made)

. xtivreg2 publish post1992 exper* dyear* 
>         (inter_shock1 =
>         inst_shock1) , 
>         fe i(unique) first cluster(unique);
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

First-stage regressions
-----------------------

First-stage regression of inter_shock1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =  3019.89
                                                      Prob > F      =   0.0000
Total (centered) SS     =  1245.361777                Centered R2   =   0.8889
Total (uncentered) SS   =  1245.361777                Uncentered R2 =   0.8889
Residual SS             =  138.3950973                Root MSE      =   .02256

------------------------------------------------------------------------------
             |               Robust
inter_shock1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0214635   .0023495     9.14   0.000     .0168581    .0260688
       exper |    -.00009   .0001798    -0.50   0.617    -.0004423    .0002624
      exper2 |   .0000153   .0000121     1.27   0.205    -8.34e-06    .0000389
      exper3 |  -4.50e-07   3.27e-07    -1.38   0.169    -1.09e-06    1.91e-07
      exper4 |   3.52e-09   2.95e-09     1.19   0.233    -2.27e-09    9.30e-09
     dyear13 |   .0002811   .0005093     0.55   0.581    -.0007172    .0012794
     dyear14 |   .0003893   .0004711     0.83   0.409    -.0005342    .0013128
     dyear15 |   .0002053   .0004302     0.48   0.633    -.0006379    .0010486
     dyear16 |   .0002356   .0003829     0.62   0.538    -.0005149    .0009861
     dyear17 |   .0001256   .0003288     0.38   0.703     -.000519    .0007702
     dyear18 |   .0001911   .0002693     0.71   0.478    -.0003368     .000719
     dyear19 |   .0002089   .0001984     1.05   0.292      -.00018    .0005978
     dyear20 |    .000088   .0001078     0.82   0.415    -.0001233    .0002993
     dyear21 |   .0000477   .0000504     0.95   0.343     -.000051    .0001464
     dyear23 |   .0006642   .0002786     2.38   0.017     .0001181    .0012102
     dyear24 |   .0006062   .0002448     2.48   0.013     .0001264     .001086
     dyear25 |   .0005453   .0002141     2.55   0.011     .0001255     .000965
     dyear26 |   .0004827   .0001861     2.59   0.010     .0001179    .0008476
     dyear27 |   .0004199   .0001604     2.62   0.009     .0001056    .0007342
     dyear28 |   .0003579   .0001366     2.62   0.009     .0000902    .0006257
     dyear29 |   .0002979   .0001148     2.60   0.009      .000073    .0005229
     dyear30 |   .0002409   .0000947     2.54   0.011     .0000552    .0004266
     dyear31 |   .0001878   .0000766     2.45   0.014     .0000377    .0003379
     dyear32 |   .0001499   .0000602     2.49   0.013     .0000319    .0002679
     dyear33 |   .0001155   .0000458     2.52   0.012     .0000258    .0002053
     dyear34 |   .0000807   .0000335     2.41   0.016      .000015    .0001465
     dyear35 |   .0000489   .0000231     2.11   0.035     3.52e-06    .0000942
     dyear36 |   .0000274   .0000151     1.81   0.070    -2.26e-06     .000057
     dyear37 |   8.36e-06   8.34e-06     1.00   0.316    -7.99e-06    .0000247
 inst_shock1 |   1.018644   .0228965    44.49   0.000     .9737628    1.063525
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_shock1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  1, 11172) =  1979.28
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =  1979.28
  Prob > F      =   0.0000



Summary results for first-stage regressions
-------------------------------------------

                                           (Underid)            (Weak id)
Variable     | F(  1, 11172)  P-val | AP Chi-sq(  1) P-val | AP F(  1, 11172)
inter_shock1 |    1979.28    0.0000 |     1979.66   0.0000 |     1979.28

NB: first-stage test statistics cluster-robust

Stock-Yogo weak ID test critical values for single endogenous regressor:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Underidentification test
Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified)
Ha: matrix has rank=K1 (identified)
Kleibergen-Paap rk LM statistic          Chi-sq(1)=1511.18  P-val=0.0000

Weak identification test
Ho: equation is weakly identified
Cragg-Donald Wald F statistic                                   87032.33
Kleibergen-Paap Wald rk F statistic                              1979.28

Stock-Yogo weak ID test critical values for K1=1 and L1=1:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Weak-instrument-robust inference
Tests of joint significance of endogenous regressors B1 in main equation
Ho: B1=0 and orthogonality conditions are valid
Anderson-Rubin Wald test           F(1,11172)=    42.91     P-val=0.0000
Anderson-Rubin Wald test           Chi-sq(1)=     42.92     P-val=0.0000
Stock-Wright LM S statistic        Chi-sq(1)=     41.73     P-val=0.0000

NB: Underidentification, weak identification and weak-identification-robust
    test statistics cluster-robust

Number of clusters             N_clust  =      11173
Number of observations               N  =     283169
Number of regressors                 K  =         30
Number of endogenous regressors      K1 =          1
Number of instruments                L  =         30
Number of excluded instruments       L1 =          1

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =   506.59
                                                      Prob > F      =   0.0000
Total (centered) SS     =  39161.08071                Centered R2   =   0.0995
Total (uncentered) SS   =  39161.08071                Uncentered R2 =   0.0995
Residual SS             =  35263.35039                Root MSE      =    .3601

------------------------------------------------------------------------------
             |               Robust
     publish |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   .5698125   .0875019     6.51   0.000      .398312    .7413131
    post1992 |  -.0964484   .0558694    -1.73   0.084    -.2059504    .0130536
       exper |  -.0607133   .0035188   -17.25   0.000      -.06761   -.0538167
      exper2 |   .0038209   .0000934    40.91   0.000     .0036379     .004004
      exper3 |  -.0000945   2.79e-06   -33.83   0.000       -.0001   -.0000891
      exper4 |   7.55e-07   2.73e-08    27.69   0.000     7.01e-07    8.08e-07
     dyear13 |   .0687569   .0304625     2.26   0.024     .0090516    .1284623
     dyear14 |    .115801   .0272374     4.25   0.000     .0624166    .1691853
     dyear15 |   .1547517   .0239419     6.46   0.000     .1078264     .201677
     dyear16 |   .1334177   .0207685     6.42   0.000     .0927122    .1741232
     dyear17 |   .1260029   .0175531     7.18   0.000     .0915995    .1604064
     dyear18 |   .1087011   .0144286     7.53   0.000     .0804215    .1369807
     dyear19 |   .1219156   .0113399    10.75   0.000     .0996898    .1441414
     dyear20 |   .1184601   .0083924    14.12   0.000     .1020112    .1349089
     dyear21 |   .0298163   .0058164     5.13   0.000     .0184164    .0412162
     dyear23 |   .0180437   .0512085     0.35   0.725    -.0823231    .1184105
     dyear24 |   .0059025   .0478804     0.12   0.902    -.0879413    .0997463
     dyear25 |   .0011721   .0445541     0.03   0.979    -.0861523    .0884965
     dyear26 |   .0150493   .0413063     0.36   0.716    -.0659097    .0960082
     dyear27 |   .0158416   .0380207     0.42   0.677    -.0586776    .0903608
     dyear28 |   .0231228     .03474     0.67   0.506    -.0449663     .091212
     dyear29 |   .0150094   .0314687     0.48   0.633    -.0466681    .0766869
     dyear30 |   .0195416   .0281501     0.69   0.488    -.0356317    .0747148
     dyear31 |   .0235707   .0248703     0.95   0.343    -.0251742    .0723155
     dyear32 |    .013289   .0216584     0.61   0.539    -.0291607    .0557386
     dyear33 |   .0137035   .0183001     0.75   0.454    -.0221641     .049571
     dyear34 |   .0058137   .0151265     0.38   0.701    -.0238337     .035461
     dyear35 |   .0074547   .0118841     0.63   0.530    -.0158376     .030747
     dyear36 |   .0045469   .0086918     0.52   0.601    -.0124886    .0215825
     dyear37 |   .0054079   .0057792     0.94   0.349    -.0059191    .0167349
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):           1511.178
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):              8.7e+04
                         (Kleibergen-Paap rk Wald F statistic):       1979.284
Stock-Yogo weak ID test critical values: 10% maximal IV size             16.38
                                         15% maximal IV size              8.96
                                         20% maximal IV size              6.66
                                         25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 publish post1992 exper* dyear* 
>         (inter_pexp1 =
>         inst_pexp1) , 
>         fe i(unique) first cluster(unique);
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

First-stage regressions
-----------------------

First-stage regression of inter_pexp1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =   449.37
                                                      Prob > F      =   0.0000
Total (centered) SS     =  1494.747919                Centered R2   =   0.5528
Total (uncentered) SS   =  1494.747919                Uncentered R2 =   0.5528
Residual SS             =   668.403453                Root MSE      =   .04957

------------------------------------------------------------------------------
             |               Robust
 inter_pexp1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0848249   .0022279    38.07   0.000     .0804578    .0891919
       exper |    .001177   .0003906     3.01   0.003     .0004112    .0019427
      exper2 |   -.000094   .0000274    -3.42   0.001    -.0001478   -.0000402
      exper3 |   2.40e-06   7.76e-07     3.10   0.002     8.81e-07    3.92e-06
      exper4 |  -1.84e-08   7.27e-09    -2.54   0.011    -3.27e-08   -4.21e-09
     dyear13 |   .0018248   .0011075     1.65   0.099     -.000346    .0039956
     dyear14 |   .0019779   .0010139     1.95   0.051    -9.58e-06    .0039654
     dyear15 |   .0017622   .0009149     1.93   0.054    -.0000312    .0035555
     dyear16 |    .002028    .000813     2.49   0.013     .0004344    .0036217
     dyear17 |   .0018439   .0007051     2.62   0.009     .0004617     .003226
     dyear18 |    .001298   .0005749     2.26   0.024      .000171     .002425
     dyear19 |   .0006829   .0004206     1.62   0.105    -.0001416    .0015074
     dyear20 |   .0003255   .0002375     1.37   0.171      -.00014     .000791
     dyear21 |   .0001309   .0001115     1.17   0.241    -.0000877    .0003495
     dyear23 |  -.0008834   .0006787    -1.30   0.193    -.0022137     .000447
     dyear24 |  -.0009125   .0006013    -1.52   0.129    -.0020911    .0002662
     dyear25 |  -.0009025   .0005296    -1.70   0.088    -.0019407    .0001357
     dyear26 |  -.0008608   .0004629    -1.86   0.063    -.0017682    .0000465
     dyear27 |  -.0007944   .0004005    -1.98   0.047    -.0015795   -9.26e-06
     dyear28 |  -.0007096   .0003424    -2.07   0.038    -.0013807   -.0000384
     dyear29 |  -.0006124   .0002884    -2.12   0.034    -.0011778   -.0000471
     dyear30 |  -.0005085   .0002387    -2.13   0.033    -.0009764   -.0000406
     dyear31 |  -.0004029   .0001935    -2.08   0.037    -.0007822   -.0000236
     dyear32 |  -.0003296    .000151    -2.18   0.029    -.0006255   -.0000337
     dyear33 |  -.0002479   .0001146    -2.16   0.031    -.0004726   -.0000232
     dyear34 |  -.0001742    .000083    -2.10   0.036     -.000337   -.0000115
     dyear35 |  -.0000962   .0000565    -1.70   0.088     -.000207    .0000145
     dyear36 |  -.0000476   .0000364    -1.31   0.191    -.0001189    .0000237
     dyear37 |  -2.43e-06   .0000195    -0.12   0.901    -.0000407    .0000358
  inst_pexp1 |   .2986035   .0225266    13.26   0.000     .2544474    .3427596
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_pexp1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  1, 11172) =   175.71
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =   175.71
  Prob > F      =   0.0000



Summary results for first-stage regressions
-------------------------------------------

                                           (Underid)            (Weak id)
Variable     | F(  1, 11172)  P-val | AP Chi-sq(  1) P-val | AP F(  1, 11172)
inter_pexp1  |     175.71    0.0000 |      175.74   0.0000 |      175.71

NB: first-stage test statistics cluster-robust

Stock-Yogo weak ID test critical values for single endogenous regressor:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Underidentification test
Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified)
Ha: matrix has rank=K1 (identified)
Kleibergen-Paap rk LM statistic          Chi-sq(1)=389.05   P-val=0.0000

Weak identification test
Ho: equation is weakly identified
Cragg-Donald Wald F statistic                                   24395.63
Kleibergen-Paap Wald rk F statistic                               175.71

Stock-Yogo weak ID test critical values for K1=1 and L1=1:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Weak-instrument-robust inference
Tests of joint significance of endogenous regressors B1 in main equation
Ho: B1=0 and orthogonality conditions are valid
Anderson-Rubin Wald test           F(1,11172)=    20.07     P-val=0.0000
Anderson-Rubin Wald test           Chi-sq(1)=     20.08     P-val=0.0000
Stock-Wright LM S statistic        Chi-sq(1)=     21.05     P-val=0.0000

NB: Underidentification, weak identification and weak-identification-robust
    test statistics cluster-robust

Number of clusters             N_clust  =      11173
Number of observations               N  =     283169
Number of regressors                 K  =         30
Number of endogenous regressors      K1 =          1
Number of instruments                L  =         30
Number of excluded instruments       L1 =          1

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =   503.24
                                                      Prob > F      =   0.0000
Total (centered) SS     =  39161.08071                Centered R2   =   0.0991
Total (uncentered) SS   =  39161.08071                Uncentered R2 =   0.0991
Residual SS             =  35278.47398                Root MSE      =    .3601

------------------------------------------------------------------------------
             |               Robust
     publish |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
 inter_pexp1 |   .3660583     .08001     4.58   0.000     .2092416    .5228751
    post1992 |  -.0637992   .0554586    -1.15   0.250    -.1724962    .0448977
       exper |  -.0609071    .003521   -17.30   0.000    -.0678082   -.0540061
      exper2 |   .0038511    .000094    40.98   0.000     .0036669    .0040352
      exper3 |  -.0000954   2.81e-06   -33.95   0.000    -.0001009   -.0000899
      exper4 |   7.61e-07   2.74e-08    27.80   0.000     7.07e-07    8.15e-07
     dyear13 |   .0693254   .0304623     2.28   0.023     .0096204    .1290303
     dyear14 |   .1164079   .0272377     4.27   0.000     .0630229    .1697928
     dyear15 |   .1552251   .0239413     6.48   0.000      .108301    .2021493
     dyear16 |   .1336296   .0207681     6.43   0.000     .0929248    .1743344
     dyear17 |   .1261474   .0175521     7.19   0.000     .0917459    .1605489
     dyear18 |   .1089017   .0144282     7.55   0.000     .0806229    .1371804
     dyear19 |   .1221288     .01134    10.77   0.000     .0999028    .1443548
     dyear20 |   .1186149   .0083922    14.13   0.000     .1021666    .1350633
     dyear21 |   .0299014    .005817     5.14   0.000     .0185002    .0413026
     dyear23 |   .0192711   .0512082     0.38   0.707    -.0810952    .1196375
     dyear24 |   .0070237   .0478804     0.15   0.883    -.0868201    .1008675
     dyear25 |   .0021807   .0445544     0.05   0.961    -.0851442    .0895057
     dyear26 |   .0159419   .0413071     0.39   0.700    -.0650185    .0969022
     dyear27 |   .0166171   .0380208     0.44   0.662    -.0579022    .0911364
     dyear28 |   .0237826   .0347402     0.68   0.494     -.044307    .0918723
     dyear29 |   .0155572   .0314686     0.49   0.621    -.0461202    .0772345
     dyear30 |    .019983   .0281503     0.71   0.478    -.0351906    .0751566
     dyear31 |   .0239134   .0248703     0.96   0.336    -.0248315    .0726582
     dyear32 |   .0135612   .0216585     0.63   0.531    -.0288887    .0560111
     dyear33 |    .013904   .0183003     0.76   0.447     -.021964     .049772
     dyear34 |   .0059517   .0151266     0.39   0.694     -.023696    .0355993
     dyear35 |   .0075349   .0118841     0.63   0.526    -.0157575    .0308273
     dyear36 |   .0045884   .0086918     0.53   0.598    -.0124472    .0216241
     dyear37 |   .0054145   .0057792     0.94   0.349    -.0059126    .0167415
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):            389.052
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):              2.4e+04
                         (Kleibergen-Paap rk Wald F statistic):        175.711
Stock-Yogo weak ID test critical values: 10% maximal IV size             16.38
                                         15% maximal IV size              8.96
                                         20% maximal IV size              6.66
                                         25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_pexp1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_pexp1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 publish post1992 exper* dyear* 
>         (inter_paut1 =
>         inst_paut1) , 
>         fe i(unique) first cluster(unique);
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

First-stage regressions
-----------------------

First-stage regression of inter_paut1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =    49.20
                                                      Prob > F      =   0.0000
Total (centered) SS     =  3048.925487                Centered R2   =   0.1384
Total (uncentered) SS   =  3048.925487                Uncentered R2 =   0.1384
Residual SS             =  2626.818728                Root MSE      =   .09828

------------------------------------------------------------------------------
             |               Robust
 inter_paut1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0612126   .0022211    27.56   0.000     .0568589    .0655662
       exper |  -.0022699   .0007826    -2.90   0.004     -.003804   -.0007358
      exper2 |   .0001527   .0000521     2.93   0.003     .0000507    .0002548
      exper3 |  -4.15e-06   1.41e-06    -2.95   0.003    -6.91e-06   -1.39e-06
      exper4 |   3.82e-08   1.27e-08     3.00   0.003     1.32e-08    6.31e-08
     dyear13 |  -.0046864    .002144    -2.19   0.029     -.008889   -.0004838
     dyear14 |  -.0047848   .0019557    -2.45   0.014    -.0086184   -.0009513
     dyear15 |  -.0046545   .0017708    -2.63   0.009    -.0081256   -.0011833
     dyear16 |  -.0035814   .0015718    -2.28   0.023    -.0066624   -.0005005
     dyear17 |  -.0029569   .0013348    -2.22   0.027    -.0055735   -.0003404
     dyear18 |  -.0032765    .001037    -3.16   0.002    -.0053091   -.0012438
     dyear19 |  -.0025495   .0007446    -3.42   0.001    -.0040091     -.00109
     dyear20 |  -.0011881   .0004633    -2.56   0.010    -.0020962   -.0002799
     dyear21 |  -.0005392   .0002158    -2.50   0.012    -.0009622   -.0001161
     dyear23 |  -.0011175   .0011314    -0.99   0.323    -.0033353    .0011003
     dyear24 |  -.0007597   .0009902    -0.77   0.443    -.0027007    .0011812
     dyear25 |  -.0004754   .0008637    -0.55   0.582    -.0021684    .0012176
     dyear26 |  -.0002543   .0007493    -0.34   0.734    -.0017231    .0012146
     dyear27 |   -.000087   .0006452    -0.13   0.893    -.0013516    .0011777
     dyear28 |   .0000349   .0005499     0.06   0.949    -.0010429    .0011127
     dyear29 |   .0001189   .0004626     0.26   0.797    -.0007879    .0010257
     dyear30 |   .0001716   .0003829     0.45   0.654     -.000579    .0009221
     dyear31 |   .0001986   .0003106     0.64   0.523    -.0004103    .0008075
     dyear32 |   .0001713   .0002459     0.70   0.486    -.0003106    .0006532
     dyear33 |   .0001796   .0001901     0.94   0.345     -.000193    .0005522
     dyear34 |   .0001639   .0001419     1.16   0.248    -.0001142     .000442
     dyear35 |   .0001063   .0001012     1.05   0.293     -.000092    .0003047
     dyear36 |   .0000815   .0000703     1.16   0.246    -.0000563    .0002193
     dyear37 |   .0000454   .0000448     1.01   0.311    -.0000424    .0001332
  inst_paut1 |   .2272155   .0205716    11.05   0.000     .1868916    .2675394
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_paut1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  1, 11172) =   121.99
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =   121.99
  Prob > F      =   0.0000



Summary results for first-stage regressions
-------------------------------------------

                                           (Underid)            (Weak id)
Variable     | F(  1, 11172)  P-val | AP Chi-sq(  1) P-val | AP F(  1, 11172)
inter_paut1  |     121.99    0.0000 |      122.02   0.0000 |      121.99

NB: first-stage test statistics cluster-robust

Stock-Yogo weak ID test critical values for single endogenous regressor:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Underidentification test
Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified)
Ha: matrix has rank=K1 (identified)
Kleibergen-Paap rk LM statistic          Chi-sq(1)=103.26   P-val=0.0000

Weak identification test
Ho: equation is weakly identified
Cragg-Donald Wald F statistic                                    9392.81
Kleibergen-Paap Wald rk F statistic                               121.99

Stock-Yogo weak ID test critical values for K1=1 and L1=1:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Weak-instrument-robust inference
Tests of joint significance of endogenous regressors B1 in main equation
Ho: B1=0 and orthogonality conditions are valid
Anderson-Rubin Wald test           F(1,11172)=     4.45     P-val=0.0349
Anderson-Rubin Wald test           Chi-sq(1)=      4.45     P-val=0.0349
Stock-Wright LM S statistic        Chi-sq(1)=      4.41     P-val=0.0358

NB: Underidentification, weak identification and weak-identification-robust
    test statistics cluster-robust

Number of clusters             N_clust  =      11173
Number of observations               N  =     283169
Number of regressors                 K  =         30
Number of endogenous regressors      K1 =          1
Number of instruments                L  =         30
Number of excluded instruments       L1 =          1

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =   495.20
                                                      Prob > F      =   0.0000
Total (centered) SS     =  39161.08071                Centered R2   =   0.0983
Total (uncentered) SS   =  39161.08071                Uncentered R2 =   0.0983
Residual SS             =  35311.71689                Root MSE      =    .3603

------------------------------------------------------------------------------
             |               Robust
     publish |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
 inter_paut1 |   .1182867   .0575989     2.05   0.040     .0053949    .2311784
    post1992 |  -.0307454   .0547114    -0.56   0.574    -.1379779     .076487
       exper |  -.0602703   .0035246   -17.10   0.000    -.0671785   -.0533622
      exper2 |    .003798   .0000944    40.24   0.000      .003613     .003983
      exper3 |   -.000094   2.82e-06   -33.32   0.000    -.0000995   -.0000884
      exper4 |   7.49e-07   2.75e-08    27.26   0.000     6.96e-07    8.03e-07
     dyear13 |   .0700806    .030464     2.30   0.021     .0103724    .1297889
     dyear14 |   .1172636   .0272397     4.30   0.000     .0638747    .1706524
     dyear15 |    .156052   .0239433     6.52   0.000      .109124      .20298
     dyear16 |   .1344598   .0207716     6.47   0.000     .0937483    .1751713
     dyear17 |   .1268839   .0175543     7.23   0.000      .092478    .1612898
     dyear18 |   .1095463   .0144309     7.59   0.000     .0812623    .1378303
     dyear19 |   .1225223   .0113411    10.80   0.000     .1002942    .1447504
     dyear20 |   .1187784   .0083926    14.15   0.000     .1023291    .1352276
     dyear21 |   .0299657   .0058165     5.15   0.000     .0185655     .041366
     dyear23 |   .0187315   .0512054     0.37   0.715    -.0816292    .1190922
     dyear24 |   .0064746   .0478778     0.14   0.892    -.0873642    .1003134
     dyear25 |    .001643   .0445518     0.04   0.971    -.0856769    .0889628
     dyear26 |   .0154321   .0413045     0.37   0.709    -.0655232    .0963874
     dyear27 |   .0161482   .0380191     0.42   0.671    -.0583678    .0906642
     dyear28 |   .0233639   .0347386     0.67   0.501    -.0447224    .0914503
     dyear29 |   .0151948   .0314674     0.48   0.629    -.0464802    .0768697
     dyear30 |     .01968   .0281492     0.70   0.484    -.0354914    .0748513
     dyear31 |   .0236702   .0248695     0.95   0.341    -.0250731    .0724135
     dyear32 |   .0133678   .0216579     0.62   0.537    -.0290808    .0558165
     dyear33 |   .0137571   .0182997     0.75   0.452    -.0221097    .0496238
     dyear34 |   .0058481   .0151263     0.39   0.699    -.0237988    .0354951
     dyear35 |   .0074757   .0118839     0.63   0.529    -.0158162    .0307677
     dyear36 |   .0045563   .0086917     0.52   0.600    -.0124792    .0215917
     dyear37 |   .0054083   .0057792     0.94   0.349    -.0059187    .0167353
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):            103.265
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             9392.811
                         (Kleibergen-Paap rk Wald F statistic):        121.995
Stock-Yogo weak ID test critical values: 10% maximal IV size             16.38
                                         15% maximal IV size              8.96
                                         20% maximal IV size              6.66
                                         25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 publish post1992 exper* dyear* 
>         (inter_shock1 inter_pexp1 inter_paut1=
>         inst_shock1 inst_pexp1 inst_paut1) , 
>         fe i(unique) first cluster(unique);
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

First-stage regressions
-----------------------

First-stage regression of inter_shock1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =  2830.45
                                                      Prob > F      =   0.0000
Total (centered) SS     =  1245.361777                Centered R2   =   0.8889
Total (uncentered) SS   =  1245.361777                Uncentered R2 =   0.8889
Residual SS             =  138.3551905                Root MSE      =   .02255

------------------------------------------------------------------------------
             |               Robust
inter_shock1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0215593    .002357     9.15   0.000     .0169391    .0261794
       exper |  -.0000887   .0001797    -0.49   0.621    -.0004409    .0002635
      exper2 |   .0000151   .0000121     1.25   0.212    -8.57e-06    .0000387
      exper3 |  -4.41e-07   3.27e-07    -1.35   0.177    -1.08e-06    2.00e-07
      exper4 |   3.42e-09   2.95e-09     1.16   0.246    -2.36e-09    9.20e-09
     dyear13 |   .0002791   .0005093     0.55   0.584    -.0007192    .0012773
     dyear14 |   .0003873    .000471     0.82   0.411    -.0005359    .0013105
     dyear15 |   .0002043   .0004301     0.47   0.635    -.0006389    .0010474
     dyear16 |   .0002317   .0003829     0.61   0.545    -.0005187    .0009822
     dyear17 |   .0001202   .0003289     0.37   0.715    -.0005245    .0007648
     dyear18 |   .0001889   .0002695     0.70   0.483    -.0003393    .0007172
     dyear19 |   .0002102   .0001986     1.06   0.290    -.0001791    .0005994
     dyear20 |   .0000872   .0001078     0.81   0.418     -.000124    .0002985
     dyear21 |   .0000473   .0000504     0.94   0.347    -.0000514     .000146
     dyear23 |   .0006596   .0002786     2.37   0.018     .0001135    .0012057
     dyear24 |   .0006021   .0002448     2.46   0.014     .0001223     .001082
     dyear25 |   .0005418   .0002141     2.53   0.011      .000122    .0009615
     dyear26 |   .0004798   .0001861     2.58   0.010     .0001149    .0008446
     dyear27 |   .0004175   .0001604     2.60   0.009     .0001032    .0007318
     dyear28 |    .000356   .0001366     2.61   0.009     .0000882    .0006238
     dyear29 |   .0002965   .0001148     2.58   0.010     .0000716    .0005214
     dyear30 |   .0002399   .0000947     2.53   0.011     .0000542    .0004256
     dyear31 |   .0001872   .0000765     2.45   0.014     .0000371    .0003372
     dyear32 |   .0001496   .0000602     2.48   0.013     .0000316    .0002676
     dyear33 |   .0001154   .0000458     2.52   0.012     .0000256    .0002051
     dyear34 |   .0000807   .0000335     2.41   0.016      .000015    .0001464
     dyear35 |   .0000489   .0000231     2.12   0.034     3.59e-06    .0000943
     dyear36 |   .0000274   .0000151     1.81   0.070    -2.24e-06     .000057
     dyear37 |   8.35e-06   8.35e-06     1.00   0.317    -8.01e-06    .0000247
 inst_shock1 |   1.016867   .0231585    43.91   0.000      .971472    1.062262
  inst_pexp1 |  -.0017663   .0047472    -0.37   0.710    -.0110717    .0075391
  inst_paut1 |   .0047924   .0029894     1.60   0.109    -.0010674    .0106521
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_shock1 inst_pexp1 inst_paut1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  3, 11172) =   667.70
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =  1428.53
  Prob > F      =   0.0000

First-stage regression of inter_pexp1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =   431.08
                                                      Prob > F      =   0.0000
Total (centered) SS     =  1494.747919                Centered R2   =   0.5605
Total (uncentered) SS   =  1494.747919                Uncentered R2 =   0.5605
Residual SS             =  656.8801205                Root MSE      =   .04915

------------------------------------------------------------------------------
             |               Robust
 inter_pexp1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0340275   .0045554     7.47   0.000     .0250982    .0429568
       exper |    .000992   .0003876     2.56   0.011     .0002321    .0017518
      exper2 |  -.0000848   .0000272    -3.11   0.002    -.0001382   -.0000314
      exper3 |   2.22e-06   7.71e-07     2.88   0.004     7.07e-07    3.73e-06
      exper4 |  -1.72e-08   7.23e-09    -2.38   0.017    -3.14e-08   -3.03e-09
     dyear13 |   .0012539   .0010991     1.14   0.254    -.0009005    .0034083
     dyear14 |   .0013521   .0010053     1.34   0.179    -.0006185    .0033227
     dyear15 |   .0011861   .0009061     1.31   0.191    -.0005901    .0029623
     dyear16 |   .0015532   .0008055     1.93   0.054    -.0000256    .0031321
     dyear17 |   .0013765   .0006984     1.97   0.049     7.53e-06    .0027455
     dyear18 |   .0009633   .0005695     1.69   0.091     -.000153    .0020796
     dyear19 |   .0005276   .0004186     1.26   0.208    -.0002929     .001348
     dyear20 |   .0002027   .0002358     0.86   0.390    -.0002594    .0006649
     dyear21 |   .0000737   .0001107     0.67   0.506    -.0001433    .0002908
     dyear23 |  -.0011019   .0006773    -1.63   0.104    -.0024295    .0002257
     dyear24 |  -.0010885   .0006004    -1.81   0.070    -.0022654    .0000885
     dyear25 |  -.0010424   .0005292    -1.97   0.049    -.0020798   -5.01e-06
     dyear26 |  -.0009704   .0004629    -2.10   0.036    -.0018778    -.000063
     dyear27 |  -.0008787   .0004009    -2.19   0.028    -.0016647   -.0000928
     dyear28 |  -.0007733   .0003431    -2.25   0.024    -.0014459   -.0001007
     dyear29 |  -.0006596   .0002895    -2.28   0.023     -.001227   -.0000922
     dyear30 |  -.0005427     .00024    -2.26   0.024    -.0010132   -.0000722
     dyear31 |  -.0004272    .000195    -2.19   0.029    -.0008094   -.0000449
     dyear32 |  -.0003477   .0001526    -2.28   0.023    -.0006469   -.0000486
     dyear33 |  -.0002595   .0001163    -2.23   0.026    -.0004874   -.0000316
     dyear34 |  -.0001823   .0000845    -2.16   0.031     -.000348   -.0000166
     dyear35 |  -.0001013   .0000578    -1.75   0.080    -.0002145    .0000119
     dyear36 |  -.0000505   .0000373    -1.35   0.176    -.0001237    .0000226
     dyear37 |  -3.45e-06   .0000197    -0.18   0.861    -.0000421    .0000352
 inst_shock1 |   .4815781   .0434569    11.08   0.000     .3963949    .5667612
  inst_pexp1 |   .2744691   .0224114    12.25   0.000     .2305388    .3183994
  inst_paut1 |   .0276587    .006365     4.35   0.000     .0151822    .0401352
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_shock1 inst_pexp1 inst_paut1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  3, 11172) =   146.73
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =   131.43
  Prob > F      =   0.0000

First-stage regression of inter_paut1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =    46.83
                                                      Prob > F      =   0.0000
Total (centered) SS     =  3048.925487                Centered R2   =   0.1473
Total (uncentered) SS   =  3048.925487                Uncentered R2 =   0.1473
Residual SS             =  2599.869398                Root MSE      =   .09777

------------------------------------------------------------------------------
             |               Robust
 inter_paut1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |  -.0190523   .0085264    -2.23   0.025    -.0357655   -.0023392
       exper |  -.0024733   .0007788    -3.18   0.001        -.004   -.0009467
      exper2 |   .0001676   .0000517     3.24   0.001     .0000661     .000269
      exper3 |  -4.51e-06   1.40e-06    -3.23   0.001    -7.25e-06   -1.77e-06
      exper4 |   4.08e-08   1.26e-08     3.23   0.001     1.60e-08    6.55e-08
     dyear13 |  -.0050104   .0021363    -2.35   0.019    -.0091978   -.0008229
     dyear14 |  -.0052171   .0019508    -2.67   0.007     -.009041   -.0013931
     dyear15 |  -.0050876    .001768    -2.88   0.004    -.0085531    -.001622
     dyear16 |  -.0038896   .0015681    -2.48   0.013    -.0069633   -.0008158
     dyear17 |  -.0032918   .0013308    -2.47   0.013    -.0059005   -.0006831
     dyear18 |   -.003515   .0010349    -3.40   0.001    -.0055437   -.0014864
     dyear19 |  -.0026184   .0007441    -3.52   0.000    -.0040769     -.00116
     dyear20 |    -.00126   .0004615    -2.73   0.006    -.0021646   -.0003554
     dyear21 |  -.0005698    .000215    -2.65   0.008    -.0009912   -.0001484
     dyear23 |  -.0010525   .0011306    -0.93   0.352    -.0032688    .0011637
     dyear24 |  -.0006814   .0009899    -0.69   0.491    -.0026218    .0012589
     dyear25 |  -.0003906   .0008638    -0.45   0.651    -.0020837    .0013025
     dyear26 |  -.0001686   .0007497    -0.22   0.822    -.0016382    .0013009
     dyear27 |  -5.09e-06   .0006458    -0.01   0.994     -.001271    .0012608
     dyear28 |   .0001095   .0005507     0.20   0.842      -.00097     .001189
     dyear29 |   .0001836   .0004636     0.40   0.692    -.0007252    .0010924
     dyear30 |   .0002248   .0003841     0.59   0.558    -.0005281    .0009776
     dyear31 |   .0002395   .0003119     0.77   0.443    -.0003719    .0008508
     dyear32 |   .0001995    .000247     0.81   0.419    -.0002847    .0006837
     dyear33 |   .0001989    .000191     1.04   0.298    -.0001755    .0005733
     dyear34 |   .0001728   .0001426     1.21   0.226    -.0001067    .0004523
     dyear35 |   .0001102   .0001019     1.08   0.280    -.0000896    .0003099
     dyear36 |   .0000823   .0000704     1.17   0.242    -.0000557    .0002202
     dyear37 |    .000044   .0000442     0.99   0.320    -.0000427    .0001306
 inst_shock1 |   .6802626   .0818528     8.31   0.000     .5198167    .8407086
  inst_pexp1 |   .0841506   .0224373     3.75   0.000     .0401695    .1281317
  inst_paut1 |   .2106196   .0207397    10.16   0.000     .1699661    .2512731
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_shock1 inst_pexp1 inst_paut1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  3, 11172) =    77.78
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =    88.89
  Prob > F      =   0.0000



Summary results for first-stage regressions
-------------------------------------------

                                           (Underid)            (Weak id)
Variable     | F(  3, 11172)  P-val | AP Chi-sq(  1) P-val | AP F(  1, 11172)
inter_shock1 |     667.70    0.0000 |     1428.82   0.0000 |     1428.53
inter_pexp1  |     146.73    0.0000 |      131.45   0.0000 |      131.43
inter_paut1  |      77.78    0.0000 |       88.91   0.0000 |       88.89

NB: first-stage test statistics cluster-robust

Stock-Yogo weak ID test critical values for single endogenous regressor:
                                    5% maximal IV relative bias    13.91
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Underidentification test
Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified)
Ha: matrix has rank=K1 (identified)
Kleibergen-Paap rk LM statistic          Chi-sq(1)=82.83    P-val=0.0000

Weak identification test
Ho: equation is weakly identified
Cragg-Donald Wald F statistic                                    2256.45
Kleibergen-Paap Wald rk F statistic                                31.51

Stock-Yogo weak ID test critical values for K1=3 and L1=3:
                                                               <not available>
Weak-instrument-robust inference
Tests of joint significance of endogenous regressors B1 in main equation
Ho: B1=0 and orthogonality conditions are valid
Anderson-Rubin Wald test           F(3,11172)=    18.76     P-val=0.0000
Anderson-Rubin Wald test           Chi-sq(3)=     56.28     P-val=0.0000
Stock-Wright LM S statistic        Chi-sq(3)=     54.67     P-val=0.0000

NB: Underidentification, weak identification and weak-identification-robust
    test statistics cluster-robust

Number of clusters             N_clust  =      11173
Number of observations               N  =     283169
Number of regressors                 K  =         32
Number of endogenous regressors      K1 =          3
Number of instruments                L  =         32
Number of excluded instruments       L1 =          3

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =   477.31
                                                      Prob > F      =   0.0000
Total (centered) SS     =  39161.08071                Centered R2   =   0.0998
Total (uncentered) SS   =  39161.08071                Uncentered R2 =   0.0998
Residual SS             =  35253.83966                Root MSE      =      .36

------------------------------------------------------------------------------
             |               Robust
     publish |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |    .356807   .1049032     3.40   0.001     .1512005    .5624135
 inter_pexp1 |    .316232   .0946373     3.34   0.001     .1307463    .5017177
 inter_paut1 |   .0089409    .067033     0.13   0.894    -.1224413    .1403232
    post1992 |  -.1053892   .0561041    -1.88   0.060    -.2153512    .0045727
       exper |  -.0609404   .0035238   -17.29   0.000     -.067847   -.0540338
      exper2 |   .0038473   .0000951    40.44   0.000     .0036609    .0040338
      exper3 |  -.0000952   2.84e-06   -33.56   0.000    -.0001008   -.0000897
      exper4 |   7.60e-07   2.76e-08    27.53   0.000     7.06e-07    8.14e-07
     dyear13 |   .0689259   .0304609     2.26   0.024     .0092237    .1286281
     dyear14 |    .115939   .0272365     4.26   0.000     .0625564    .1693216
     dyear15 |   .1548454   .0239394     6.47   0.000     .1079249    .2017658
     dyear16 |   .1333301   .0207678     6.42   0.000     .0926259    .1740342
     dyear17 |   .1258861   .0175515     7.17   0.000     .0914859    .1602864
     dyear18 |   .1086803   .0144288     7.53   0.000     .0804005    .1369602
     dyear19 |   .1219848   .0113406    10.76   0.000     .0997576     .144212
     dyear20 |   .1185189   .0083917    14.12   0.000     .1020715    .1349662
     dyear21 |   .0298532   .0058168     5.13   0.000     .0184524     .041254
     dyear23 |   .0188436   .0512095     0.37   0.713    -.0815251    .1192123
     dyear24 |   .0066432   .0478814     0.14   0.890    -.0872025    .1004889
     dyear25 |   .0018461   .0445557     0.04   0.967    -.0854815    .0891736
     dyear26 |   .0156513   .0413083     0.38   0.705    -.0653114    .0966141
     dyear27 |   .0163687   .0380221     0.43   0.667    -.0581533    .0908906
     dyear28 |   .0235739   .0347413     0.68   0.497    -.0445178    .0916657
     dyear29 |   .0153855   .0314698     0.49   0.625    -.0462941    .0770651
     dyear30 |   .0198453   .0281513     0.70   0.481    -.0353302    .0750207
     dyear31 |   .0238064   .0248711     0.96   0.338    -.0249401    .0725528
     dyear32 |   .0134757   .0216591     0.62   0.534    -.0289753    .0559267
     dyear33 |   .0138397   .0183009     0.76   0.450    -.0220294    .0497087
     dyear34 |    .005906    .015127     0.39   0.696    -.0237423    .0355544
     dyear35 |   .0075074   .0118843     0.63   0.528    -.0157854    .0308002
     dyear36 |   .0045731    .008692     0.53   0.599    -.0124629    .0216091
     dyear37 |   .0054103   .0057792     0.94   0.349    -.0059168    .0167374
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):             82.833
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             2256.450
                         (Kleibergen-Paap rk Wald F statistic):         31.512
Stock-Yogo weak ID test critical values:                       <not available>
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1 inter_pexp1 inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1 inst_pexp1 inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 papers post1992 exper* dyear* 
>         (inter_shock1 =
>         inst_shock1) , 
>         fe i(unique) first cluster(unique);
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

First-stage regressions
-----------------------

First-stage regression of inter_shock1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =  3019.89
                                                      Prob > F      =   0.0000
Total (centered) SS     =  1245.361777                Centered R2   =   0.8889
Total (uncentered) SS   =  1245.361777                Uncentered R2 =   0.8889
Residual SS             =  138.3950973                Root MSE      =   .02256

------------------------------------------------------------------------------
             |               Robust
inter_shock1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0214635   .0023495     9.14   0.000     .0168581    .0260688
       exper |    -.00009   .0001798    -0.50   0.617    -.0004423    .0002624
      exper2 |   .0000153   .0000121     1.27   0.205    -8.34e-06    .0000389
      exper3 |  -4.50e-07   3.27e-07    -1.38   0.169    -1.09e-06    1.91e-07
      exper4 |   3.52e-09   2.95e-09     1.19   0.233    -2.27e-09    9.30e-09
     dyear13 |   .0002811   .0005093     0.55   0.581    -.0007172    .0012794
     dyear14 |   .0003893   .0004711     0.83   0.409    -.0005342    .0013128
     dyear15 |   .0002053   .0004302     0.48   0.633    -.0006379    .0010486
     dyear16 |   .0002356   .0003829     0.62   0.538    -.0005149    .0009861
     dyear17 |   .0001256   .0003288     0.38   0.703     -.000519    .0007702
     dyear18 |   .0001911   .0002693     0.71   0.478    -.0003368     .000719
     dyear19 |   .0002089   .0001984     1.05   0.292      -.00018    .0005978
     dyear20 |    .000088   .0001078     0.82   0.415    -.0001233    .0002993
     dyear21 |   .0000477   .0000504     0.95   0.343     -.000051    .0001464
     dyear23 |   .0006642   .0002786     2.38   0.017     .0001181    .0012102
     dyear24 |   .0006062   .0002448     2.48   0.013     .0001264     .001086
     dyear25 |   .0005453   .0002141     2.55   0.011     .0001255     .000965
     dyear26 |   .0004827   .0001861     2.59   0.010     .0001179    .0008476
     dyear27 |   .0004199   .0001604     2.62   0.009     .0001056    .0007342
     dyear28 |   .0003579   .0001366     2.62   0.009     .0000902    .0006257
     dyear29 |   .0002979   .0001148     2.60   0.009      .000073    .0005229
     dyear30 |   .0002409   .0000947     2.54   0.011     .0000552    .0004266
     dyear31 |   .0001878   .0000766     2.45   0.014     .0000377    .0003379
     dyear32 |   .0001499   .0000602     2.49   0.013     .0000319    .0002679
     dyear33 |   .0001155   .0000458     2.52   0.012     .0000258    .0002053
     dyear34 |   .0000807   .0000335     2.41   0.016      .000015    .0001465
     dyear35 |   .0000489   .0000231     2.11   0.035     3.52e-06    .0000942
     dyear36 |   .0000274   .0000151     1.81   0.070    -2.26e-06     .000057
     dyear37 |   8.36e-06   8.34e-06     1.00   0.316    -7.99e-06    .0000247
 inst_shock1 |   1.018644   .0228965    44.49   0.000     .9737628    1.063525
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_shock1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  1, 11172) =  1979.28
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =  1979.28
  Prob > F      =   0.0000



Summary results for first-stage regressions
-------------------------------------------

                                           (Underid)            (Weak id)
Variable     | F(  1, 11172)  P-val | AP Chi-sq(  1) P-val | AP F(  1, 11172)
inter_shock1 |    1979.28    0.0000 |     1979.66   0.0000 |     1979.28

NB: first-stage test statistics cluster-robust

Stock-Yogo weak ID test critical values for single endogenous regressor:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Underidentification test
Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified)
Ha: matrix has rank=K1 (identified)
Kleibergen-Paap rk LM statistic          Chi-sq(1)=1511.18  P-val=0.0000

Weak identification test
Ho: equation is weakly identified
Cragg-Donald Wald F statistic                                   87032.33
Kleibergen-Paap Wald rk F statistic                              1979.28

Stock-Yogo weak ID test critical values for K1=1 and L1=1:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Weak-instrument-robust inference
Tests of joint significance of endogenous regressors B1 in main equation
Ho: B1=0 and orthogonality conditions are valid
Anderson-Rubin Wald test           F(1,11172)=    10.00     P-val=0.0016
Anderson-Rubin Wald test           Chi-sq(1)=     10.00     P-val=0.0016
Stock-Wright LM S statistic        Chi-sq(1)=      9.95     P-val=0.0016

NB: Underidentification, weak identification and weak-identification-robust
    test statistics cluster-robust

Number of clusters             N_clust  =      11173
Number of observations               N  =     283169
Number of regressors                 K  =         30
Number of endogenous regressors      K1 =          1
Number of instruments                L  =         30
Number of excluded instruments       L1 =          1

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =   130.63
                                                      Prob > F      =   0.0000
Total (centered) SS     =  221391.4874                Centered R2   =   0.0315
Total (uncentered) SS   =  221391.4874                Uncentered R2 =   0.0315
Residual SS             =   214407.436                Root MSE      =    .8878

------------------------------------------------------------------------------
             |               Robust
      papers |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   .7908168   .2498741     3.16   0.002     .3010725    1.280561
    post1992 |  -.4581333   .1417823    -3.23   0.001    -.7360215   -.1802452
       exper |  -.0492241   .0090777    -5.42   0.000    -.0670161   -.0314321
      exper2 |   .0042547   .0003073    13.85   0.000     .0036524     .004857
      exper3 |  -.0000978   9.77e-06   -10.00   0.000    -.0001169   -.0000786
      exper4 |   6.51e-07   1.00e-07     6.50   0.000     4.55e-07    8.47e-07
     dyear13 |   .1990701   .0771943     2.58   0.010     .0477719    .3503682
     dyear14 |   .2673959   .0688456     3.88   0.000      .132461    .4023307
     dyear15 |   .3165073    .060628     5.22   0.000     .1976785    .4353361
     dyear16 |   .2912939   .0522641     5.57   0.000      .188858    .3937297
     dyear17 |   .2519127   .0445137     5.66   0.000     .1646675    .3391579
     dyear18 |   .1895854   .0358723     5.29   0.000      .119277    .2598937
     dyear19 |   .2093163    .028291     7.40   0.000      .153867    .2647656
     dyear20 |   .2064948   .0205314    10.06   0.000     .1662541    .2467356
     dyear21 |   .0569845   .0134157     4.25   0.000     .0306902    .0832788
     dyear23 |   .3075172    .129958     2.37   0.018     .0528041    .5622303
     dyear24 |   .2450973   .1215259     2.02   0.044     .0069108    .4832838
     dyear25 |   .2222486   .1129821     1.97   0.049     .0008077    .4436896
     dyear26 |   .2741242   .1049953     2.61   0.009     .0683372    .4799111
     dyear27 |   .2418219   .0965459     2.50   0.012     .0525954    .4310484
     dyear28 |    .247101   .0882342     2.80   0.005     .0741652    .4200368
     dyear29 |   .2176657   .0798466     2.73   0.006     .0611693    .3741621
     dyear30 |   .2139354   .0713982     3.00   0.003     .0739974    .3538733
     dyear31 |   .2039481   .0631893     3.23   0.001     .0800994    .3277969
     dyear32 |   .1484477   .0546663     2.72   0.007     .0413037    .2555917
     dyear33 |   .1423128   .0463131     3.07   0.002     .0515408    .2330849
     dyear34 |   .0935833   .0379291     2.47   0.014     .0192435     .167923
     dyear35 |   .0626479   .0296957     2.11   0.035     .0044454    .1208504
     dyear36 |   .0421817    .021798     1.94   0.053    -.0005415     .084905
     dyear37 |   .0232312   .0142335     1.63   0.103    -.0046661    .0511284
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):           1511.178
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):              8.7e+04
                         (Kleibergen-Paap rk Wald F statistic):       1979.284
Stock-Yogo weak ID test critical values: 10% maximal IV size             16.38
                                         15% maximal IV size              8.96
                                         20% maximal IV size              6.66
                                         25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 papers post1992 exper* dyear* 
>         (inter_pexp1 =
>         inst_pexp1) , 
>         fe i(unique) first cluster(unique);
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

First-stage regressions
-----------------------

First-stage regression of inter_pexp1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =   449.37
                                                      Prob > F      =   0.0000
Total (centered) SS     =  1494.747919                Centered R2   =   0.5528
Total (uncentered) SS   =  1494.747919                Uncentered R2 =   0.5528
Residual SS             =   668.403453                Root MSE      =   .04957

------------------------------------------------------------------------------
             |               Robust
 inter_pexp1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0848249   .0022279    38.07   0.000     .0804578    .0891919
       exper |    .001177   .0003906     3.01   0.003     .0004112    .0019427
      exper2 |   -.000094   .0000274    -3.42   0.001    -.0001478   -.0000402
      exper3 |   2.40e-06   7.76e-07     3.10   0.002     8.81e-07    3.92e-06
      exper4 |  -1.84e-08   7.27e-09    -2.54   0.011    -3.27e-08   -4.21e-09
     dyear13 |   .0018248   .0011075     1.65   0.099     -.000346    .0039956
     dyear14 |   .0019779   .0010139     1.95   0.051    -9.58e-06    .0039654
     dyear15 |   .0017622   .0009149     1.93   0.054    -.0000312    .0035555
     dyear16 |    .002028    .000813     2.49   0.013     .0004344    .0036217
     dyear17 |   .0018439   .0007051     2.62   0.009     .0004617     .003226
     dyear18 |    .001298   .0005749     2.26   0.024      .000171     .002425
     dyear19 |   .0006829   .0004206     1.62   0.105    -.0001416    .0015074
     dyear20 |   .0003255   .0002375     1.37   0.171      -.00014     .000791
     dyear21 |   .0001309   .0001115     1.17   0.241    -.0000877    .0003495
     dyear23 |  -.0008834   .0006787    -1.30   0.193    -.0022137     .000447
     dyear24 |  -.0009125   .0006013    -1.52   0.129    -.0020911    .0002662
     dyear25 |  -.0009025   .0005296    -1.70   0.088    -.0019407    .0001357
     dyear26 |  -.0008608   .0004629    -1.86   0.063    -.0017682    .0000465
     dyear27 |  -.0007944   .0004005    -1.98   0.047    -.0015795   -9.26e-06
     dyear28 |  -.0007096   .0003424    -2.07   0.038    -.0013807   -.0000384
     dyear29 |  -.0006124   .0002884    -2.12   0.034    -.0011778   -.0000471
     dyear30 |  -.0005085   .0002387    -2.13   0.033    -.0009764   -.0000406
     dyear31 |  -.0004029   .0001935    -2.08   0.037    -.0007822   -.0000236
     dyear32 |  -.0003296    .000151    -2.18   0.029    -.0006255   -.0000337
     dyear33 |  -.0002479   .0001146    -2.16   0.031    -.0004726   -.0000232
     dyear34 |  -.0001742    .000083    -2.10   0.036     -.000337   -.0000115
     dyear35 |  -.0000962   .0000565    -1.70   0.088     -.000207    .0000145
     dyear36 |  -.0000476   .0000364    -1.31   0.191    -.0001189    .0000237
     dyear37 |  -2.43e-06   .0000195    -0.12   0.901    -.0000407    .0000358
  inst_pexp1 |   .2986035   .0225266    13.26   0.000     .2544474    .3427596
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_pexp1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  1, 11172) =   175.71
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =   175.71
  Prob > F      =   0.0000



Summary results for first-stage regressions
-------------------------------------------

                                           (Underid)            (Weak id)
Variable     | F(  1, 11172)  P-val | AP Chi-sq(  1) P-val | AP F(  1, 11172)
inter_pexp1  |     175.71    0.0000 |      175.74   0.0000 |      175.71

NB: first-stage test statistics cluster-robust

Stock-Yogo weak ID test critical values for single endogenous regressor:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Underidentification test
Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified)
Ha: matrix has rank=K1 (identified)
Kleibergen-Paap rk LM statistic          Chi-sq(1)=389.05   P-val=0.0000

Weak identification test
Ho: equation is weakly identified
Cragg-Donald Wald F statistic                                   24395.63
Kleibergen-Paap Wald rk F statistic                               175.71

Stock-Yogo weak ID test critical values for K1=1 and L1=1:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Weak-instrument-robust inference
Tests of joint significance of endogenous regressors B1 in main equation
Ho: B1=0 and orthogonality conditions are valid
Anderson-Rubin Wald test           F(1,11172)=     2.21     P-val=0.1368
Anderson-Rubin Wald test           Chi-sq(1)=      2.21     P-val=0.1367
Stock-Wright LM S statistic        Chi-sq(1)=      2.27     P-val=0.1316

NB: Underidentification, weak identification and weak-identification-robust
    test statistics cluster-robust

Number of clusters             N_clust  =      11173
Number of observations               N  =     283169
Number of regressors                 K  =         30
Number of endogenous regressors      K1 =          1
Number of instruments                L  =         30
Number of excluded instruments       L1 =          1

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =   129.93
                                                      Prob > F      =   0.0000
Total (centered) SS     =  221391.4874                Centered R2   =   0.0315
Total (uncentered) SS   =  221391.4874                Uncentered R2 =   0.0315
Residual SS             =  214419.7515                Root MSE      =    .8879

------------------------------------------------------------------------------
             |               Robust
      papers |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
 inter_pexp1 |   .4706082   .3100725     1.52   0.129    -.1371227    1.078339
    post1992 |  -.4085473   .1436888    -2.84   0.004    -.6901722   -.1269224
       exper |  -.0494565   .0090822    -5.45   0.000    -.0672572   -.0316557
      exper2 |   .0042931   .0003097    13.86   0.000      .003686    .0049002
      exper3 |  -.0000989   9.84e-06   -10.05   0.000    -.0001182   -.0000796
      exper4 |   6.59e-07   1.01e-07     6.56   0.000     4.62e-07    8.56e-07
     dyear13 |   .1998772   .0771863     2.59   0.010     .0485948    .3511595
     dyear14 |   .2682659   .0688343     3.90   0.000     .1333531    .4031788
     dyear15 |   .3171907   .0606195     5.23   0.000     .1983786    .4360028
     dyear16 |   .2916295    .052253     5.58   0.000     .1892155    .3940435
     dyear17 |   .2521542   .0445037     5.67   0.000     .1649285    .3393799
     dyear18 |   .1898899    .035866     5.29   0.000     .1195937     .260186
     dyear19 |   .2096195   .0282899     7.41   0.000     .1541723    .2650666
     dyear20 |   .2067119   .0205291    10.07   0.000     .1664756    .2469481
     dyear21 |   .0571025   .0134148     4.26   0.000       .03081    .0833951
     dyear23 |   .3091517   .1299607     2.38   0.017     .0544335      .56387
     dyear24 |   .2465877   .1215309     2.03   0.042     .0083914     .484784
     dyear25 |   .2235875   .1129868     1.98   0.048     .0021375    .4450375
     dyear26 |   .2753074    .105002     2.62   0.009     .0695074    .4811075
     dyear27 |   .2428489   .0965496     2.52   0.012     .0536152    .4320827
     dyear28 |   .2479741   .0882386     2.81   0.005     .0750296    .4209185
     dyear29 |     .21839   .0798484     2.74   0.006     .0618899    .3748901
     dyear30 |   .2145188    .071401     3.00   0.003     .0745754    .3544621
     dyear31 |    .204401   .0631913     3.23   0.001     .0805483    .3282536
     dyear32 |   .1488075   .0546683     2.72   0.006     .0416596    .2559554
     dyear33 |   .1425781    .046314     3.08   0.002     .0518042    .2333519
     dyear34 |    .093766   .0379296     2.47   0.013     .0194253    .1681066
     dyear35 |   .0627544   .0296959     2.11   0.035     .0045514    .1209574
     dyear36 |    .042237   .0217984     1.94   0.053     -.000487     .084961
     dyear37 |   .0232402   .0142335     1.63   0.103    -.0046569    .0511374
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):            389.052
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):              2.4e+04
                         (Kleibergen-Paap rk Wald F statistic):        175.711
Stock-Yogo weak ID test critical values: 10% maximal IV size             16.38
                                         15% maximal IV size              8.96
                                         20% maximal IV size              6.66
                                         25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_pexp1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_pexp1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 papers post1992 exper* dyear* 
>         (inter_paut1 =
>         inst_paut1) , 
>         fe i(unique) first cluster(unique);
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

First-stage regressions
-----------------------

First-stage regression of inter_paut1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =    49.20
                                                      Prob > F      =   0.0000
Total (centered) SS     =  3048.925487                Centered R2   =   0.1384
Total (uncentered) SS   =  3048.925487                Uncentered R2 =   0.1384
Residual SS             =  2626.818728                Root MSE      =   .09828

------------------------------------------------------------------------------
             |               Robust
 inter_paut1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0612126   .0022211    27.56   0.000     .0568589    .0655662
       exper |  -.0022699   .0007826    -2.90   0.004     -.003804   -.0007358
      exper2 |   .0001527   .0000521     2.93   0.003     .0000507    .0002548
      exper3 |  -4.15e-06   1.41e-06    -2.95   0.003    -6.91e-06   -1.39e-06
      exper4 |   3.82e-08   1.27e-08     3.00   0.003     1.32e-08    6.31e-08
     dyear13 |  -.0046864    .002144    -2.19   0.029     -.008889   -.0004838
     dyear14 |  -.0047848   .0019557    -2.45   0.014    -.0086184   -.0009513
     dyear15 |  -.0046545   .0017708    -2.63   0.009    -.0081256   -.0011833
     dyear16 |  -.0035814   .0015718    -2.28   0.023    -.0066624   -.0005005
     dyear17 |  -.0029569   .0013348    -2.22   0.027    -.0055735   -.0003404
     dyear18 |  -.0032765    .001037    -3.16   0.002    -.0053091   -.0012438
     dyear19 |  -.0025495   .0007446    -3.42   0.001    -.0040091     -.00109
     dyear20 |  -.0011881   .0004633    -2.56   0.010    -.0020962   -.0002799
     dyear21 |  -.0005392   .0002158    -2.50   0.012    -.0009622   -.0001161
     dyear23 |  -.0011175   .0011314    -0.99   0.323    -.0033353    .0011003
     dyear24 |  -.0007597   .0009902    -0.77   0.443    -.0027007    .0011812
     dyear25 |  -.0004754   .0008637    -0.55   0.582    -.0021684    .0012176
     dyear26 |  -.0002543   .0007493    -0.34   0.734    -.0017231    .0012146
     dyear27 |   -.000087   .0006452    -0.13   0.893    -.0013516    .0011777
     dyear28 |   .0000349   .0005499     0.06   0.949    -.0010429    .0011127
     dyear29 |   .0001189   .0004626     0.26   0.797    -.0007879    .0010257
     dyear30 |   .0001716   .0003829     0.45   0.654     -.000579    .0009221
     dyear31 |   .0001986   .0003106     0.64   0.523    -.0004103    .0008075
     dyear32 |   .0001713   .0002459     0.70   0.486    -.0003106    .0006532
     dyear33 |   .0001796   .0001901     0.94   0.345     -.000193    .0005522
     dyear34 |   .0001639   .0001419     1.16   0.248    -.0001142     .000442
     dyear35 |   .0001063   .0001012     1.05   0.293     -.000092    .0003047
     dyear36 |   .0000815   .0000703     1.16   0.246    -.0000563    .0002193
     dyear37 |   .0000454   .0000448     1.01   0.311    -.0000424    .0001332
  inst_paut1 |   .2272155   .0205716    11.05   0.000     .1868916    .2675394
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_paut1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  1, 11172) =   121.99
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =   121.99
  Prob > F      =   0.0000



Summary results for first-stage regressions
-------------------------------------------

                                           (Underid)            (Weak id)
Variable     | F(  1, 11172)  P-val | AP Chi-sq(  1) P-val | AP F(  1, 11172)
inter_paut1  |     121.99    0.0000 |      122.02   0.0000 |      121.99

NB: first-stage test statistics cluster-robust

Stock-Yogo weak ID test critical values for single endogenous regressor:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Underidentification test
Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified)
Ha: matrix has rank=K1 (identified)
Kleibergen-Paap rk LM statistic          Chi-sq(1)=103.26   P-val=0.0000

Weak identification test
Ho: equation is weakly identified
Cragg-Donald Wald F statistic                                    9392.81
Kleibergen-Paap Wald rk F statistic                               121.99

Stock-Yogo weak ID test critical values for K1=1 and L1=1:
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Weak-instrument-robust inference
Tests of joint significance of endogenous regressors B1 in main equation
Ho: B1=0 and orthogonality conditions are valid
Anderson-Rubin Wald test           F(1,11172)=     0.43     P-val=0.5134
Anderson-Rubin Wald test           Chi-sq(1)=      0.43     P-val=0.5133
Stock-Wright LM S statistic        Chi-sq(1)=      0.43     P-val=0.5139

NB: Underidentification, weak identification and weak-identification-robust
    test statistics cluster-robust

Number of clusters             N_clust  =      11173
Number of observations               N  =     283169
Number of regressors                 K  =         30
Number of endogenous regressors      K1 =          1
Number of instruments                L  =         30
Number of excluded instruments       L1 =          1

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 30, 11172) =   128.28
                                                      Prob > F      =   0.0000
Total (centered) SS     =  221391.4874                Centered R2   =   0.0309
Total (uncentered) SS   =  221391.4874                Uncentered R2 =   0.0309
Residual SS             =  214544.7917                Root MSE      =    .8881

------------------------------------------------------------------------------
             |               Robust
      papers |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
 inter_paut1 |   .0923645   .1418604     0.65   0.515    -.1856768    .3704057
    post1992 |  -.3616385     .13899    -2.60   0.009    -.6340538   -.0892231
       exper |  -.0487783   .0090903    -5.37   0.000     -.066595   -.0309616
      exper2 |   .0042346   .0003089    13.71   0.000     .0036291      .00484
      exper3 |  -.0000973   9.81e-06    -9.92   0.000    -.0001165   -.0000781
      exper4 |   6.47e-07   1.00e-07     6.45   0.000     4.50e-07    8.44e-07
     dyear13 |   .2005567   .0771984     2.60   0.009     .0492506    .3518628
     dyear14 |   .2690711   .0688517     3.91   0.000     .1341242     .404018
     dyear15 |   .3179665   .0606321     5.24   0.000     .1991297    .4368033
     dyear16 |   .2924827   .0522636     5.60   0.000     .1900478    .3949175
     dyear17 |   .2529314   .0445168     5.68   0.000       .16568    .3401827
     dyear18 |   .1905221    .035872     5.31   0.000     .1202144    .2608299
     dyear19 |   .2099626   .0282919     7.42   0.000     .1545116    .2654137
     dyear20 |   .2068497   .0205309    10.08   0.000     .1666099    .2470894
     dyear21 |   .0571525   .0134133     4.26   0.000      .030863     .083442
     dyear23 |   .3083896   .1299502     2.37   0.018      .053692    .5630872
     dyear24 |    .245835   .1215198     2.02   0.043     .0076606    .4840093
     dyear25 |   .2228664   .1129762     1.97   0.049      .001437    .4442957
     dyear26 |   .2746355    .104991     2.62   0.009      .068857     .480414
     dyear27 |   .2422395   .0965419     2.51   0.012     .0530209    .4314581
     dyear28 |   .2474364    .088231     2.80   0.005     .0745068     .420366
     dyear29 |   .2179297   .0798437     2.73   0.006      .061439    .3744205
     dyear30 |    .214138   .0713961     3.00   0.003     .0742042    .3540717
     dyear31 |   .2040987   .0631877     3.23   0.001     .0802531    .3279442
     dyear32 |   .1485677   .0546655     2.72   0.007     .0414252    .2557101
     dyear33 |   .1423988   .0463121     3.07   0.002     .0516287    .2331688
     dyear34 |   .0936418   .0379284     2.47   0.014     .0193034    .1679801
     dyear35 |   .0626839   .0296954     2.11   0.035     .0044821    .1208858
     dyear36 |   .0422002    .021798     1.94   0.053     -.000523    .0849234
     dyear37 |   .0232351   .0142335     1.63   0.103     -.004662    .0511322
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):            103.265
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             9392.811
                         (Kleibergen-Paap rk Wald F statistic):        121.995
Stock-Yogo weak ID test critical values: 10% maximal IV size             16.38
                                         15% maximal IV size              8.96
                                         20% maximal IV size              6.66
                                         25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 papers post1992 exper* dyear* 
>         (inter_shock1 inter_pexp1 inter_paut1=
>         inst_shock1 inst_pexp1 inst_paut1) , 
>         fe i(unique) first cluster(unique);
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

First-stage regressions
-----------------------

First-stage regression of inter_shock1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =  2830.45
                                                      Prob > F      =   0.0000
Total (centered) SS     =  1245.361777                Centered R2   =   0.8889
Total (uncentered) SS   =  1245.361777                Uncentered R2 =   0.8889
Residual SS             =  138.3551905                Root MSE      =   .02255

------------------------------------------------------------------------------
             |               Robust
inter_shock1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0215593    .002357     9.15   0.000     .0169391    .0261794
       exper |  -.0000887   .0001797    -0.49   0.621    -.0004409    .0002635
      exper2 |   .0000151   .0000121     1.25   0.212    -8.57e-06    .0000387
      exper3 |  -4.41e-07   3.27e-07    -1.35   0.177    -1.08e-06    2.00e-07
      exper4 |   3.42e-09   2.95e-09     1.16   0.246    -2.36e-09    9.20e-09
     dyear13 |   .0002791   .0005093     0.55   0.584    -.0007192    .0012773
     dyear14 |   .0003873    .000471     0.82   0.411    -.0005359    .0013105
     dyear15 |   .0002043   .0004301     0.47   0.635    -.0006389    .0010474
     dyear16 |   .0002317   .0003829     0.61   0.545    -.0005187    .0009822
     dyear17 |   .0001202   .0003289     0.37   0.715    -.0005245    .0007648
     dyear18 |   .0001889   .0002695     0.70   0.483    -.0003393    .0007172
     dyear19 |   .0002102   .0001986     1.06   0.290    -.0001791    .0005994
     dyear20 |   .0000872   .0001078     0.81   0.418     -.000124    .0002985
     dyear21 |   .0000473   .0000504     0.94   0.347    -.0000514     .000146
     dyear23 |   .0006596   .0002786     2.37   0.018     .0001135    .0012057
     dyear24 |   .0006021   .0002448     2.46   0.014     .0001223     .001082
     dyear25 |   .0005418   .0002141     2.53   0.011      .000122    .0009615
     dyear26 |   .0004798   .0001861     2.58   0.010     .0001149    .0008446
     dyear27 |   .0004175   .0001604     2.60   0.009     .0001032    .0007318
     dyear28 |    .000356   .0001366     2.61   0.009     .0000882    .0006238
     dyear29 |   .0002965   .0001148     2.58   0.010     .0000716    .0005214
     dyear30 |   .0002399   .0000947     2.53   0.011     .0000542    .0004256
     dyear31 |   .0001872   .0000765     2.45   0.014     .0000371    .0003372
     dyear32 |   .0001496   .0000602     2.48   0.013     .0000316    .0002676
     dyear33 |   .0001154   .0000458     2.52   0.012     .0000256    .0002051
     dyear34 |   .0000807   .0000335     2.41   0.016      .000015    .0001464
     dyear35 |   .0000489   .0000231     2.12   0.034     3.59e-06    .0000943
     dyear36 |   .0000274   .0000151     1.81   0.070    -2.24e-06     .000057
     dyear37 |   8.35e-06   8.35e-06     1.00   0.317    -8.01e-06    .0000247
 inst_shock1 |   1.016867   .0231585    43.91   0.000      .971472    1.062262
  inst_pexp1 |  -.0017663   .0047472    -0.37   0.710    -.0110717    .0075391
  inst_paut1 |   .0047924   .0029894     1.60   0.109    -.0010674    .0106521
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_shock1 inst_pexp1 inst_paut1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  3, 11172) =   667.70
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =  1428.53
  Prob > F      =   0.0000

First-stage regression of inter_pexp1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =   431.08
                                                      Prob > F      =   0.0000
Total (centered) SS     =  1494.747919                Centered R2   =   0.5605
Total (uncentered) SS   =  1494.747919                Uncentered R2 =   0.5605
Residual SS             =  656.8801205                Root MSE      =   .04915

------------------------------------------------------------------------------
             |               Robust
 inter_pexp1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |   .0340275   .0045554     7.47   0.000     .0250982    .0429568
       exper |    .000992   .0003876     2.56   0.011     .0002321    .0017518
      exper2 |  -.0000848   .0000272    -3.11   0.002    -.0001382   -.0000314
      exper3 |   2.22e-06   7.71e-07     2.88   0.004     7.07e-07    3.73e-06
      exper4 |  -1.72e-08   7.23e-09    -2.38   0.017    -3.14e-08   -3.03e-09
     dyear13 |   .0012539   .0010991     1.14   0.254    -.0009005    .0034083
     dyear14 |   .0013521   .0010053     1.34   0.179    -.0006185    .0033227
     dyear15 |   .0011861   .0009061     1.31   0.191    -.0005901    .0029623
     dyear16 |   .0015532   .0008055     1.93   0.054    -.0000256    .0031321
     dyear17 |   .0013765   .0006984     1.97   0.049     7.53e-06    .0027455
     dyear18 |   .0009633   .0005695     1.69   0.091     -.000153    .0020796
     dyear19 |   .0005276   .0004186     1.26   0.208    -.0002929     .001348
     dyear20 |   .0002027   .0002358     0.86   0.390    -.0002594    .0006649
     dyear21 |   .0000737   .0001107     0.67   0.506    -.0001433    .0002908
     dyear23 |  -.0011019   .0006773    -1.63   0.104    -.0024295    .0002257
     dyear24 |  -.0010885   .0006004    -1.81   0.070    -.0022654    .0000885
     dyear25 |  -.0010424   .0005292    -1.97   0.049    -.0020798   -5.01e-06
     dyear26 |  -.0009704   .0004629    -2.10   0.036    -.0018778    -.000063
     dyear27 |  -.0008787   .0004009    -2.19   0.028    -.0016647   -.0000928
     dyear28 |  -.0007733   .0003431    -2.25   0.024    -.0014459   -.0001007
     dyear29 |  -.0006596   .0002895    -2.28   0.023     -.001227   -.0000922
     dyear30 |  -.0005427     .00024    -2.26   0.024    -.0010132   -.0000722
     dyear31 |  -.0004272    .000195    -2.19   0.029    -.0008094   -.0000449
     dyear32 |  -.0003477   .0001526    -2.28   0.023    -.0006469   -.0000486
     dyear33 |  -.0002595   .0001163    -2.23   0.026    -.0004874   -.0000316
     dyear34 |  -.0001823   .0000845    -2.16   0.031     -.000348   -.0000166
     dyear35 |  -.0001013   .0000578    -1.75   0.080    -.0002145    .0000119
     dyear36 |  -.0000505   .0000373    -1.35   0.176    -.0001237    .0000226
     dyear37 |  -3.45e-06   .0000197    -0.18   0.861    -.0000421    .0000352
 inst_shock1 |   .4815781   .0434569    11.08   0.000     .3963949    .5667612
  inst_pexp1 |   .2744691   .0224114    12.25   0.000     .2305388    .3183994
  inst_paut1 |   .0276587    .006365     4.35   0.000     .0151822    .0401352
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_shock1 inst_pexp1 inst_paut1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  3, 11172) =   146.73
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =   131.43
  Prob > F      =   0.0000

First-stage regression of inter_paut1:

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

OLS estimation
--------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =    46.83
                                                      Prob > F      =   0.0000
Total (centered) SS     =  3048.925487                Centered R2   =   0.1473
Total (uncentered) SS   =  3048.925487                Uncentered R2 =   0.1473
Residual SS             =  2599.869398                Root MSE      =   .09777

------------------------------------------------------------------------------
             |               Robust
 inter_paut1 |      Coef.   Std. Err.      t    P>|t|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
    post1992 |  -.0190523   .0085264    -2.23   0.025    -.0357655   -.0023392
       exper |  -.0024733   .0007788    -3.18   0.001        -.004   -.0009467
      exper2 |   .0001676   .0000517     3.24   0.001     .0000661     .000269
      exper3 |  -4.51e-06   1.40e-06    -3.23   0.001    -7.25e-06   -1.77e-06
      exper4 |   4.08e-08   1.26e-08     3.23   0.001     1.60e-08    6.55e-08
     dyear13 |  -.0050104   .0021363    -2.35   0.019    -.0091978   -.0008229
     dyear14 |  -.0052171   .0019508    -2.67   0.007     -.009041   -.0013931
     dyear15 |  -.0050876    .001768    -2.88   0.004    -.0085531    -.001622
     dyear16 |  -.0038896   .0015681    -2.48   0.013    -.0069633   -.0008158
     dyear17 |  -.0032918   .0013308    -2.47   0.013    -.0059005   -.0006831
     dyear18 |   -.003515   .0010349    -3.40   0.001    -.0055437   -.0014864
     dyear19 |  -.0026184   .0007441    -3.52   0.000    -.0040769     -.00116
     dyear20 |    -.00126   .0004615    -2.73   0.006    -.0021646   -.0003554
     dyear21 |  -.0005698    .000215    -2.65   0.008    -.0009912   -.0001484
     dyear23 |  -.0010525   .0011306    -0.93   0.352    -.0032688    .0011637
     dyear24 |  -.0006814   .0009899    -0.69   0.491    -.0026218    .0012589
     dyear25 |  -.0003906   .0008638    -0.45   0.651    -.0020837    .0013025
     dyear26 |  -.0001686   .0007497    -0.22   0.822    -.0016382    .0013009
     dyear27 |  -5.09e-06   .0006458    -0.01   0.994     -.001271    .0012608
     dyear28 |   .0001095   .0005507     0.20   0.842      -.00097     .001189
     dyear29 |   .0001836   .0004636     0.40   0.692    -.0007252    .0010924
     dyear30 |   .0002248   .0003841     0.59   0.558    -.0005281    .0009776
     dyear31 |   .0002395   .0003119     0.77   0.443    -.0003719    .0008508
     dyear32 |   .0001995    .000247     0.81   0.419    -.0002847    .0006837
     dyear33 |   .0001989    .000191     1.04   0.298    -.0001755    .0005733
     dyear34 |   .0001728   .0001426     1.21   0.226    -.0001067    .0004523
     dyear35 |   .0001102   .0001019     1.08   0.280    -.0000896    .0003099
     dyear36 |   .0000823   .0000704     1.17   0.242    -.0000557    .0002202
     dyear37 |    .000044   .0000442     0.99   0.320    -.0000427    .0001306
 inst_shock1 |   .6802626   .0818528     8.31   0.000     .5198167    .8407086
  inst_pexp1 |   .0841506   .0224373     3.75   0.000     .0401695    .1281317
  inst_paut1 |   .2106196   .0207397    10.16   0.000     .1699661    .2512731
------------------------------------------------------------------------------
Warning: estimated covariance matrix of moment conditions not of full rank.
         model tests should be interpreted with caution.
Possible causes:
         number of clusters insufficient to calculate robust covariance matrix
         singleton dummy variable (dummy with one 1 and N-1 0s or vice versa)
partial option may address problem.
------------------------------------------------------------------------------
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37 inst_shock1 inst_pexp1 inst_paut1
------------------------------------------------------------------------------
F test of excluded instruments:
  F(  3, 11172) =    77.78
  Prob > F      =   0.0000
Angrist-Pischke multivariate F test of excluded instruments:
  F(  1, 11172) =    88.89
  Prob > F      =   0.0000



Summary results for first-stage regressions
-------------------------------------------

                                           (Underid)            (Weak id)
Variable     | F(  3, 11172)  P-val | AP Chi-sq(  1) P-val | AP F(  1, 11172)
inter_shock1 |     667.70    0.0000 |     1428.82   0.0000 |     1428.53
inter_pexp1  |     146.73    0.0000 |      131.45   0.0000 |      131.43
inter_paut1  |      77.78    0.0000 |       88.91   0.0000 |       88.89

NB: first-stage test statistics cluster-robust

Stock-Yogo weak ID test critical values for single endogenous regressor:
                                    5% maximal IV relative bias    13.91
                                   10% maximal IV size             16.38
                                   15% maximal IV size              8.96
                                   20% maximal IV size              6.66
                                   25% maximal IV size              5.53
Source: Stock-Yogo (2005).  Reproduced by permission.
NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors.

Underidentification test
Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified)
Ha: matrix has rank=K1 (identified)
Kleibergen-Paap rk LM statistic          Chi-sq(1)=82.83    P-val=0.0000

Weak identification test
Ho: equation is weakly identified
Cragg-Donald Wald F statistic                                    2256.45
Kleibergen-Paap Wald rk F statistic                                31.51

Stock-Yogo weak ID test critical values for K1=3 and L1=3:
                                                               <not available>
Weak-instrument-robust inference
Tests of joint significance of endogenous regressors B1 in main equation
Ho: B1=0 and orthogonality conditions are valid
Anderson-Rubin Wald test           F(3,11172)=     3.54     P-val=0.0140
Anderson-Rubin Wald test           Chi-sq(3)=     10.62     P-val=0.0139
Stock-Wright LM S statistic        Chi-sq(3)=     10.59     P-val=0.0141

NB: Underidentification, weak identification and weak-identification-robust
    test statistics cluster-robust

Number of clusters             N_clust  =      11173
Number of observations               N  =     283169
Number of regressors                 K  =         32
Number of endogenous regressors      K1 =          3
Number of instruments                L  =         32
Number of excluded instruments       L1 =          3

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =   123.46
                                                      Prob > F      =   0.0000
Total (centered) SS     =  221391.4874                Centered R2   =   0.0319
Total (uncentered) SS   =  221391.4874                Uncentered R2 =   0.0319
Residual SS             =  214327.5298                Root MSE      =    .8877

------------------------------------------------------------------------------
             |               Robust
      papers |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   .5632793   .2943166     1.91   0.056    -.0135706    1.140129
 inter_pexp1 |   .4321239   .3645729     1.19   0.236    -.2824259    1.146674
 inter_paut1 |  -.0634675   .1725028    -0.37   0.713    -.4015667    .2746317
    post1992 |  -.4730553   .1430178    -3.31   0.001    -.7533651   -.1927456
       exper |  -.0497309   .0090958    -5.47   0.000    -.0675584   -.0319034
      exper2 |   .0043035   .0003133    13.74   0.000     .0036895    .0049176
      exper3 |  -.0000991   9.92e-06    -9.99   0.000    -.0001185   -.0000796
      exper4 |   6.61e-07   1.01e-07     6.54   0.000     4.63e-07    8.60e-07
     dyear13 |   .1988483   .0771884     2.58   0.010     .0475619    .3501347
     dyear14 |   .2671127   .0688433     3.88   0.000     .1321822    .4020432
     dyear15 |   .3161897   .0606251     5.22   0.000     .1973666    .4350127
     dyear16 |   .2908338   .0522633     5.56   0.000     .1883996    .3932679
     dyear17 |   .2514773   .0445091     5.65   0.000     .1642411    .3387135
     dyear18 |   .1892571   .0358667     5.28   0.000     .1189597    .2595546
     dyear19 |   .2091729   .0282889     7.39   0.000     .1537276    .2646182
     dyear20 |   .2064641   .0205275    10.06   0.000     .1662309    .2466972
     dyear21 |    .056984   .0134136     4.25   0.000     .0306938    .0832743
     dyear23 |    .308462   .1299739     2.37   0.018     .0537178    .5632063
     dyear24 |   .2459966   .1215428     2.02   0.043     .0077772    .4842161
     dyear25 |   .2230859   .1129982     1.97   0.048     .0016135    .4445584
     dyear26 |   .2748868    .105012     2.62   0.009     .0690671    .4807066
     dyear27 |   .2425011   .0965583     2.51   0.012     .0532502    .4317519
     dyear28 |   .2476912   .0882459     2.81   0.005     .0747324    .4206501
     dyear29 |   .2181648   .0798548     2.73   0.006     .0616523    .3746773
     dyear30 |   .2143441   .0714061     3.00   0.003     .0743906    .3542976
     dyear31 |   .2042699   .0631955     3.23   0.001     .0804089    .3281309
     dyear32 |   .1487032   .0546714     2.72   0.007     .0415491    .2558572
     dyear33 |   .1425031   .0463167     3.08   0.002     .0517239    .2332822
     dyear34 |   .0937149   .0379309     2.47   0.013     .0193717    .1680582
     dyear35 |   .0627235   .0296967     2.11   0.035      .004519     .120928
     dyear36 |   .0422212    .021799     1.94   0.053    -.0005041    .0849466
     dyear37 |   .0232372   .0142336     1.63   0.103    -.0046601    .0511346
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):             82.833
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             2256.450
                         (Kleibergen-Paap rk Wald F statistic):         31.512
Stock-Yogo weak ID test critical values:                       <not available>
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1 inter_pexp1 inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1 inst_pexp1 inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. *****************;
. *MERGING IN DATA THAT HAS DEPENDENT VARIABLES "TOP JOURNALS" AND "COAUTHOR SHARE
> ";
. *REGRESSIONS IN COLUMNS 5 AND 6 OF TABLE 4;
. *REGRESSIONS WILL BE RUN USING TWO SPECIFICATIONS;
. *MISSING WILL BE TREATED AS MISSING OR SET TO ZERO;
. sort unique year;

. merge unique year using /volumes/ddisk/math/soviet/hard_outcome_variables.dta;
(note: you are using old merge syntax; see [D] merge for new syntax)

. drop _merge;

. rename author_share_papers share_of_papers;

. generate top_publish=(top_papers>0);

. replace top_publish=. if top_papers==.;
(16095 real changes made, 16095 to missing)

. xtivreg2 top_publish post1992 exper* dyear* 
>         (inter_shock1 inter_pexp1 inter_paut1=
>         inst_shock1 inst_pexp1 inst_paut1) , 
>         fe i(unique) cluster(unique);
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     10472                    Obs per group: min =        19
                                                               avg =      25.5
                                                               max =        27

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    10472                Number of obs =   267074
                                                      F( 32, 10471) =    21.33
                                                      Prob > F      =   0.0000
Total (centered) SS     =  3417.129653                Centered R2   =   0.0027
Total (uncentered) SS   =  3417.129653                Uncentered R2 =   0.0027
Residual SS             =  3407.930582                Root MSE      =    .1152

------------------------------------------------------------------------------
             |               Robust
 top_publish |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   .3898368   .0505092     7.72   0.000     .2908406     .488833
 inter_pexp1 |   -.022882    .050354    -0.45   0.650    -.1215741    .0758101
 inter_paut1 |  -.0239681   .0328094    -0.73   0.465    -.0882734    .0403372
    post1992 |  -.0553177   .0183394    -3.02   0.003    -.0912623   -.0193732
       exper |   .0018196   .0011387     1.60   0.110    -.0004121    .0040514
      exper2 |  -.0000663   .0000348    -1.90   0.057    -.0001346    1.95e-06
      exper3 |   1.62e-06   1.01e-06     1.60   0.109    -3.64e-07    3.61e-06
      exper4 |  -2.24e-08   9.90e-09    -2.26   0.024    -4.18e-08   -2.96e-09
     dyear13 |   .0238162   .0097474     2.44   0.015     .0047117    .0429207
     dyear14 |    .016265   .0086616     1.88   0.060    -.0007114    .0332415
     dyear15 |   .0235179   .0077157     3.05   0.002     .0083954    .0386403
     dyear16 |   .0191402   .0066413     2.88   0.004     .0061235    .0321568
     dyear17 |   .0192136   .0056525     3.40   0.001     .0081349    .0302923
     dyear18 |   .0168107   .0046362     3.63   0.000     .0077239    .0258974
     dyear19 |   .0155877   .0036887     4.23   0.000      .008358    .0228175
     dyear20 |   .0044014   .0026829     1.64   0.101     -.000857    .0096599
     dyear21 |    .003117   .0019533     1.60   0.111    -.0007113    .0069454
     dyear23 |   -.000613   .0161918    -0.04   0.970    -.0323484    .0311223
     dyear24 |  -.0017682    .015215    -0.12   0.907     -.031589    .0280526
     dyear25 |  -.0018016   .0141123    -0.13   0.898    -.0294613     .025858
     dyear26 |  -.0016691    .013051    -0.13   0.898    -.0272486    .0239104
     dyear27 |  -.0018483   .0119625    -0.15   0.877    -.0252943    .0215977
     dyear28 |  -.0000474   .0109661    -0.00   0.997    -.0215406    .0214458
     dyear29 |  -.0004672   .0099909    -0.05   0.963    -.0200489    .0191146
     dyear30 |  -.0011966   .0089568    -0.13   0.894    -.0187515    .0163584
     dyear31 |  -.0003239   .0078521    -0.04   0.967    -.0157138    .0150659
     dyear32 |  -.0028105   .0068534    -0.41   0.682    -.0162428    .0106218
     dyear33 |  -.0015027   .0057726    -0.26   0.795    -.0128167    .0098114
     dyear34 |  -.0018445    .004721    -0.39   0.696    -.0110974    .0074084
     dyear35 |    .000364   .0037538     0.10   0.923    -.0069934    .0077214
     dyear36 |   .0003492   .0027675     0.13   0.900     -.005075    .0057734
     dyear37 |  -.0018936   .0017905    -1.06   0.290     -.005403    .0016158
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):             77.749
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             2032.236
                         (Kleibergen-Paap rk Wald F statistic):         29.430
Stock-Yogo weak ID test critical values:                       <not available>
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1 inter_pexp1 inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1 inst_pexp1 inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 top_papers post1992 exper* dyear* 
>         (inter_shock1 inter_pexp1 inter_paut1=
>         inst_shock1 inst_pexp1 inst_paut1) , 
>         fe i(unique) cluster(unique);
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     10472                    Obs per group: min =        19
                                                               avg =      25.5
                                                               max =        27

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    10472                Number of obs =   267074
                                                      F( 32, 10471) =    15.75
                                                      Prob > F      =   0.0000
Total (centered) SS     =  6952.809397                Centered R2   =   0.0022
Total (uncentered) SS   =  6952.809397                Uncentered R2 =   0.0022
Residual SS             =  6937.806614                Root MSE      =    .1644

------------------------------------------------------------------------------
             |               Robust
  top_papers |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   .5553097   .0761777     7.29   0.000     .4060041    .7046153
 inter_pexp1 |   .0144913   .0718351     0.20   0.840    -.1263029    .1552854
 inter_paut1 |  -.0151211   .0510836    -0.30   0.767    -.1152432     .085001
    post1992 |  -.0732477   .0295544    -2.48   0.013    -.1311733   -.0153221
       exper |    .002124   .0018673     1.14   0.255    -.0015359    .0057839
      exper2 |  -.0001033   .0000569    -1.82   0.070    -.0002149    8.25e-06
      exper3 |   2.96e-06   1.71e-06     1.74   0.083    -3.82e-07    6.30e-06
      exper4 |  -4.09e-08   1.73e-08    -2.37   0.018    -7.47e-08   -7.05e-09
     dyear13 |   .0253981   .0156301     1.62   0.104    -.0052363    .0560325
     dyear14 |   .0141463    .013842     1.02   0.307    -.0129835    .0412761
     dyear15 |   .0257203   .0122263     2.10   0.035     .0017572    .0496835
     dyear16 |   .0212065   .0105109     2.02   0.044     .0006055    .0418076
     dyear17 |   .0198722   .0088373     2.25   0.025     .0025514     .037193
     dyear18 |   .0190461    .007253     2.63   0.009     .0048304    .0332617
     dyear19 |    .018413   .0056704     3.25   0.001     .0072991    .0295268
     dyear20 |   .0049557   .0039771     1.25   0.213    -.0028394    .0127507
     dyear21 |   .0027114   .0025893     1.05   0.295    -.0023635    .0077864
     dyear23 |  -.0068789   .0263587    -0.26   0.794    -.0585411    .0447833
     dyear24 |  -.0089138    .024746    -0.36   0.719     -.057415    .0395875
     dyear25 |  -.0098985   .0228432    -0.43   0.665    -.0546704    .0348734
     dyear26 |  -.0083067   .0210586    -0.39   0.693    -.0495808    .0329675
     dyear27 |  -.0071948   .0194252    -0.37   0.711    -.0452674    .0308779
     dyear28 |  -.0050344   .0178079    -0.28   0.777    -.0399372    .0298685
     dyear29 |  -.0042115   .0162022    -0.26   0.795    -.0359673    .0275443
     dyear30 |  -.0053922   .0145184    -0.37   0.710    -.0338477    .0230634
     dyear31 |  -.0014112   .0127373    -0.11   0.912    -.0263758    .0235535
     dyear32 |  -.0065652   .0111638    -0.59   0.556    -.0284458    .0153154
     dyear33 |  -.0040505   .0094367    -0.43   0.668     -.022546     .014445
     dyear34 |  -.0030275   .0075188    -0.40   0.687     -.017764     .011709
     dyear35 |  -.0020222   .0061415    -0.33   0.742    -.0140593    .0100149
     dyear36 |  -.0011847   .0044666    -0.27   0.791    -.0099392    .0075698
     dyear37 |  -.0029206   .0028158    -1.04   0.300    -.0084394    .0025982
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):             77.749
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             2032.236
                         (Kleibergen-Paap rk Wald F statistic):         29.430
Stock-Yogo weak ID test critical values:                       <not available>
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1 inter_pexp1 inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1 inst_pexp1 inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 share_of_papers post1992 exper* dyear* 
>         (inter_shock1 inter_pexp1 inter_paut1=
>         inst_shock1 inst_pexp1 inst_paut1) , 
>         fe i(unique) cluster(unique);
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     10472                    Obs per group: min =        19
                                                               avg =      25.5
                                                               max =        27

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    10472                Number of obs =   267074
                                                      F( 32, 10471) =   107.69
                                                      Prob > F      =   0.0000
Total (centered) SS     =  107256.7413                Centered R2   =   0.0299
Total (uncentered) SS   =  107256.7413                Uncentered R2 =   0.0299
Residual SS             =  104052.9141                Root MSE      =    .6368

------------------------------------------------------------------------------
             |               Robust
share_of_p~s |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   .9967177    .211088     4.72   0.000     .5829927    1.410443
 inter_pexp1 |   .3710038   .2276045     1.63   0.103    -.0750927    .8171004
 inter_paut1 |   .2102644   .1319712     1.59   0.111    -.0483945    .4689232
    post1992 |  -.5490573   .1012942    -5.42   0.000    -.7475903   -.3505242
       exper |  -.0209383   .0064266    -3.26   0.001    -.0335342   -.0083424
      exper2 |   .0023918   .0002051    11.66   0.000     .0019897    .0027939
      exper3 |  -.0000557   6.33e-06    -8.80   0.000    -.0000681   -.0000433
      exper4 |   3.89e-07   6.34e-08     6.14   0.000     2.65e-07    5.13e-07
     dyear13 |   .2112529   .0550981     3.83   0.000     .1032627    .3192431
     dyear14 |   .2340876   .0492211     4.76   0.000     .1376159    .3305592
     dyear15 |    .257949   .0434215     5.94   0.000     .1728445    .3430535
     dyear16 |    .246945   .0374243     6.60   0.000     .1735946    .3202954
     dyear17 |   .2139773   .0316819     6.75   0.000     .1518819    .2760727
     dyear18 |   .1761117   .0258118     6.82   0.000     .1255214    .2267019
     dyear19 |   .1585898   .0203108     7.81   0.000     .1187813    .1983982
     dyear20 |   .1568019   .0149236    10.51   0.000     .1275521    .1860517
     dyear21 |   .0482657   .0099716     4.84   0.000     .0287217    .0678096
     dyear23 |    .318033   .0921422     3.45   0.001     .1374376    .4986283
     dyear24 |   .2565082    .086072     2.98   0.003     .0878101    .4252063
     dyear25 |   .2320108   .0799675     2.90   0.004     .0752775    .3887442
     dyear26 |   .2498805   .0742523     3.37   0.001     .1043486    .3954124
     dyear27 |   .2443484   .0684586     3.57   0.000      .110172    .3785248
     dyear28 |   .2409396   .0624427     3.86   0.000     .1185541    .3633251
     dyear29 |   .2135288    .056531     3.78   0.000       .10273    .3243276
     dyear30 |   .1953539   .0506046     3.86   0.000     .0961707    .2945371
     dyear31 |   .1866577   .0447156     4.17   0.000     .0990166    .2742987
     dyear32 |   .1506428   .0387382     3.89   0.000     .0747174    .2265681
     dyear33 |   .1345839   .0328423     4.10   0.000     .0702142    .1989536
     dyear34 |   .0962407   .0269799     3.57   0.000     .0433611    .1491204
     dyear35 |   .0603268   .0210767     2.86   0.004     .0190173    .1016364
     dyear36 |   .0430902   .0153485     2.81   0.005     .0130077    .0731726
     dyear37 |   .0244745   .0100503     2.44   0.015     .0047763    .0441728
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):             77.749
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             2032.236
                         (Kleibergen-Paap rk Wald F statistic):         29.430
Stock-Yogo weak ID test critical values:                       <not available>
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1 inter_pexp1 inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1 inst_pexp1 inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. replace share_of_papers=0 if share_of_papers==.;
(17093 real changes made)

. replace top_publish=0 if top_publish==.;
(16095 real changes made)

. replace top_papers=0 if top_papers==.;
(16095 real changes made)

. xtivreg2 top_publish post1992 exper* dyear* 
>         (inter_shock1 inter_pexp1 inter_paut1=
>         inst_shock1 inst_pexp1 inst_paut1) , 
>         fe i(unique) cluster(unique);
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =    21.31
                                                      Prob > F      =   0.0000
Total (centered) SS     =  3417.129653                Centered R2   =   0.0025
Total (uncentered) SS   =  3417.129653                Uncentered R2 =   0.0025
Residual SS             =  3408.626277                Root MSE      =    .1119

------------------------------------------------------------------------------
             |               Robust
 top_publish |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   .3756624   .0484335     7.76   0.000     .2807345    .4705903
 inter_pexp1 |  -.0230952   .0483148    -0.48   0.633    -.1177905    .0716001
 inter_paut1 |  -.0258633   .0316485    -0.82   0.414    -.0878932    .0361666
    post1992 |  -.0532158    .017199    -3.09   0.002    -.0869252   -.0195064
       exper |    .001971   .0010679     1.85   0.065    -.0001221    .0040641
      exper2 |  -.0000791   .0000334    -2.37   0.018    -.0001446   -.0000136
      exper3 |   1.97e-06   9.82e-07     2.01   0.045     4.71e-08    3.89e-06
      exper4 |  -2.54e-08   9.66e-09    -2.63   0.009    -4.43e-08   -6.47e-09
     dyear13 |   .0235686   .0091559     2.57   0.010     .0056235    .0415138
     dyear14 |    .016053   .0081302     1.97   0.048     .0001182    .0319878
     dyear15 |   .0230816   .0072477     3.18   0.001     .0088764    .0372868
     dyear16 |   .0187353   .0062358     3.00   0.003     .0065134    .0309572
     dyear17 |   .0186853   .0053085     3.52   0.000     .0082809    .0290898
     dyear18 |   .0162592   .0043527     3.74   0.000     .0077281    .0247903
     dyear19 |   .0149406   .0034636     4.31   0.000     .0081521     .021729
     dyear20 |   .0043267   .0025148     1.72   0.085    -.0006023    .0092556
     dyear21 |   .0030147   .0018305     1.65   0.100    -.0005731    .0066025
     dyear23 |  -.0002089   .0151657    -0.01   0.989    -.0299332    .0295154
     dyear24 |  -.0013597   .0142512    -0.10   0.924    -.0292915    .0265721
     dyear25 |  -.0014487   .0132184    -0.11   0.913    -.0273563    .0244589
     dyear26 |  -.0013729   .0122247    -0.11   0.911    -.0253328     .022587
     dyear27 |  -.0015813   .0112054    -0.14   0.888    -.0235434    .0203807
     dyear28 |   .0000732   .0102723     0.01   0.994    -.0200601    .0202065
     dyear29 |  -.0003476    .009359    -0.04   0.970    -.0186908    .0179956
     dyear30 |  -.0010534   .0083904    -0.13   0.900    -.0174983    .0153915
     dyear31 |  -.0002532   .0073557    -0.03   0.973    -.0146701    .0141638
     dyear32 |  -.0025986   .0064203    -0.40   0.686    -.0151821    .0099848
     dyear33 |  -.0013844   .0054078    -0.26   0.798    -.0119834    .0092146
     dyear34 |  -.0017134   .0044227    -0.39   0.698    -.0103817    .0069548
     dyear35 |   .0003493   .0035168     0.10   0.921    -.0065434     .007242
     dyear36 |   .0003312   .0025928     0.13   0.898    -.0047505    .0054129
     dyear37 |  -.0017734   .0016775    -1.06   0.290    -.0050613    .0015145
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):             82.833
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             2256.450
                         (Kleibergen-Paap rk Wald F statistic):         31.512
Stock-Yogo weak ID test critical values:                       <not available>
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1 inter_pexp1 inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1 inst_pexp1 inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 top_papers post1992 exper* dyear* 
>         (inter_shock1 inter_pexp1 inter_paut1=
>         inst_shock1 inst_pexp1 inst_paut1) , 
>         fe i(unique) cluster(unique);
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =    15.75
                                                      Prob > F      =   0.0000
Total (centered) SS     =  6952.809397                Centered R2   =   0.0021
Total (uncentered) SS   =  6952.809397                Uncentered R2 =   0.0021
Residual SS             =  6938.386272                Root MSE      =    .1597

------------------------------------------------------------------------------
             |               Robust
  top_papers |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   .5317857   .0729198     7.29   0.000     .3888654    .6747059
 inter_pexp1 |   .0119422   .0689057     0.17   0.862    -.1231104    .1469949
 inter_paut1 |  -.0148223   .0494252    -0.30   0.764    -.1116939    .0820494
    post1992 |  -.0702048   .0277203    -2.53   0.011    -.1245356    -.015874
       exper |   .0022334   .0017531     1.27   0.203    -.0012026    .0056694
      exper2 |  -.0001144   .0000545    -2.10   0.036    -.0002211   -7.64e-06
      exper3 |   3.29e-06   1.65e-06     1.99   0.046     5.65e-08    6.53e-06
      exper4 |  -4.39e-08   1.69e-08    -2.60   0.009    -7.69e-08   -1.09e-08
     dyear13 |   .0249958    .014675     1.70   0.089    -.0037668    .0537583
     dyear14 |   .0138558   .0129888     1.07   0.286    -.0116018    .0393135
     dyear15 |   .0251169   .0114804     2.19   0.029     .0026158     .047618
     dyear16 |   .0206289   .0098659     2.09   0.037     .0012921    .0399658
     dyear17 |   .0192243   .0082965     2.32   0.020     .0029634    .0354851
     dyear18 |   .0183139   .0068102     2.69   0.007     .0049661    .0316617
     dyear19 |   .0175593   .0053254     3.30   0.001     .0071217    .0279969
     dyear20 |   .0048334   .0037311     1.30   0.195    -.0024795    .0121462
     dyear21 |   .0026278   .0024278     1.08   0.279    -.0021307    .0073863
     dyear23 |   -.006143   .0246985    -0.25   0.804    -.0545512    .0422653
     dyear24 |  -.0081109   .0231871    -0.35   0.726    -.0535568    .0373349
     dyear25 |  -.0090842   .0214033    -0.42   0.671    -.0510339    .0328655
     dyear26 |  -.0076336   .0197311    -0.39   0.699    -.0463057    .0310386
     dyear27 |   -.006625   .0182009    -0.36   0.716    -.0422981     .029048
     dyear28 |  -.0046273   .0166851    -0.28   0.782    -.0373295    .0280748
     dyear29 |  -.0038777   .0151805    -0.26   0.798     -.033631    .0258755
     dyear30 |  -.0050014   .0136027    -0.37   0.713    -.0316623    .0216594
     dyear31 |  -.0012835   .0119339    -0.11   0.914    -.0246734    .0221064
     dyear32 |  -.0061253   .0104594    -0.59   0.558    -.0266255    .0143748
     dyear33 |  -.0037772   .0088411    -0.43   0.669    -.0211054     .013551
     dyear34 |  -.0028251   .0070442    -0.40   0.688    -.0166314    .0109813
     dyear35 |  -.0018883   .0057539    -0.33   0.743    -.0131657    .0093891
     dyear36 |  -.0011067   .0041847    -0.26   0.791    -.0093087    .0070952
     dyear37 |  -.0027358   .0026381    -1.04   0.300    -.0079063    .0024347
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):             82.833
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             2256.450
                         (Kleibergen-Paap rk Wald F statistic):         31.512
Stock-Yogo weak ID test critical values:                       <not available>
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1 inter_pexp1 inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1 inst_pexp1 inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. xtivreg2 share_of_papers post1992 exper* dyear* 
>         (inter_shock1 inter_pexp1 inter_paut1=
>         inst_shock1 inst_pexp1 inst_paut1) , 
>         fe i(unique) cluster(unique);
Warning - collinearities detected
Vars dropped:  dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8 dyear9
               dyear10 dyear11 dyear12 dyear22 dyear38 dyear39

FIXED EFFECTS ESTIMATION
------------------------
Number of groups =     11173                    Obs per group: min =        19
                                                               avg =      25.3
                                                               max =        27

IV (2SLS) estimation
--------------------

Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on unique

Number of clusters (unique) =    11173                Number of obs =   283169
                                                      F( 32, 11172) =   103.87
                                                      Prob > F      =   0.0000
Total (centered) SS     =  107256.7413                Centered R2   =   0.0284
Total (uncentered) SS   =  107256.7413                Uncentered R2 =   0.0284
Residual SS             =  104205.8832                Root MSE      =     .619

------------------------------------------------------------------------------
             |               Robust
share_of_p~s |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]
-------------+----------------------------------------------------------------
inter_shock1 |   1.048699   .2031212     5.16   0.000      .650589    1.446809
 inter_pexp1 |   .3742657   .2187625     1.71   0.087     -.054501    .8030323
 inter_paut1 |   .1032476   .1245117     0.83   0.407    -.1407909     .347286
    post1992 |  -.5269029   .0949797    -5.55   0.000    -.7130597    -.340746
       exper |  -.0144954   .0060411    -2.40   0.016    -.0263357    -.002655
      exper2 |   .0019509   .0001982     9.84   0.000     .0015624    .0023395
      exper3 |  -.0000455   6.16e-06    -7.39   0.000    -.0000575   -.0000334
      exper4 |   3.08e-07   6.19e-08     4.98   0.000     1.87e-07    4.29e-07
     dyear13 |   .2115914   .0517057     4.09   0.000     .1102501    .3129327
     dyear14 |   .2326661   .0461956     5.04   0.000     .1421244    .3232078
     dyear15 |   .2548602   .0407566     6.25   0.000     .1749788    .3347416
     dyear16 |   .2427844   .0351293     6.91   0.000     .1739321    .3116366
     dyear17 |   .2089484   .0297378     7.03   0.000     .1506634    .2672334
     dyear18 |   .1710408   .0242264     7.06   0.000      .123558    .2185236
     dyear19 |    .152479   .0190651     8.00   0.000     .1151121    .1898459
     dyear20 |   .1484478   .0139982    10.60   0.000     .1210117    .1758838
     dyear21 |   .0459078   .0093479     4.91   0.000     .0275863    .0642293
     dyear23 |    .299704   .0863254     3.47   0.001     .1305093    .4688988
     dyear24 |    .241602   .0806377     3.00   0.003     .0835551    .3996489
     dyear25 |    .218297   .0749188     2.91   0.004      .071459    .3651351
     dyear26 |   .2347796   .0695651     3.37   0.001     .0984346    .3711247
     dyear27 |   .2293947   .0641375     3.58   0.000     .1036874    .3551019
     dyear28 |   .2260546   .0585023     3.86   0.000     .1113921    .3407171
     dyear29 |   .2002631   .0529632     3.78   0.000     .0964571    .3040691
     dyear30 |   .1831641   .0474112     3.86   0.000     .0902399    .2760883
     dyear31 |   .1749781   .0418937     4.18   0.000      .092868    .2570882
     dyear32 |   .1411731   .0362932     3.89   0.000     .0700397    .2123065
     dyear33 |   .1261053   .0307692     4.10   0.000     .0657988    .1864118
     dyear34 |   .0901659   .0252766     3.57   0.000     .0406246    .1397071
     dyear35 |   .0565032   .0197463     2.86   0.004     .0178012    .0952053
     dyear36 |   .0403624   .0143795     2.81   0.005     .0121792    .0685456
     dyear37 |   .0229202   .0094161     2.43   0.015      .004465    .0413753
------------------------------------------------------------------------------
Underidentification test (Kleibergen-Paap rk LM statistic):             82.833
                                                   Chi-sq(1) P-val =    0.0000
------------------------------------------------------------------------------
Weak identification test (Cragg-Donald Wald F statistic):             2256.450
                         (Kleibergen-Paap rk Wald F statistic):         31.512
Stock-Yogo weak ID test critical values:                       <not available>
------------------------------------------------------------------------------
Hansen J statistic (overidentification test of all instruments):         0.000
                                                 (equation exactly identified)
------------------------------------------------------------------------------
Instrumented:         inter_shock1 inter_pexp1 inter_paut1
Included instruments: post1992 exper exper2 exper3 exper4 dyear13 dyear14
                      dyear15 dyear16 dyear17 dyear18 dyear19 dyear20 dyear21
                      dyear23 dyear24 dyear25 dyear26 dyear27 dyear28 dyear29
                      dyear30 dyear31 dyear32 dyear33 dyear34 dyear35 dyear36
                      dyear37
Excluded instruments: inst_shock1 inst_pexp1 inst_paut1
Dropped collinear:    dyear1 dyear2 dyear3 dyear4 dyear5 dyear6 dyear7 dyear8
                      dyear9 dyear10 dyear11 dyear12 dyear22 dyear38 dyear39
------------------------------------------------------------------------------

. log close;
      name:  <unnamed>
       log:  /volumes/ddisk/math/soviet/Tables_3_and_4.log
  log type:  text
 closed on:  24 Mar 2014, 13:24:53
----------------------------------------------------------------------------------
